MDedge Infectious Disease

New data present further evidence that SARS-CoV-2 infection can settle in the gastrointestinal tract and that it can persist long after the infection has cleared the lungs.

Infection of the GI tract may figure prominently in long COVID, the study authors suggested.

Led by Aravind Natarajan, PhD, with the departments of genetics and medicine at Stanford (Calif.) University, they analyzed fecal RNA shedding up to 10 months after a COVID-19 diagnosis in 673 stool samples from 113 patients with mild to moderate disease.

They found that, in the week after diagnosis, COVID RNA remnants were present in the stool of approximately half (49.2%) of the patients. Seven months later, about 4% of them shed fecal viral RNA.

The authors noted that there was no ongoing SARS-CoV-2 RNA shedding in respiratory samples of patients at the 4-month mark.

Using self-reported symptoms regularly collected by questionnaire, they also found a correlation of long-term fecal shedding of SARS-CoV-2 RNA with abdominal pain, nausea, and vomiting.

The findings were published online in Med.
 

Implications of long-term viral shedding

Previous studies have found SARS-CoV-2 RNA in respiratory and fecal samples and have documented viral replication in lung and intestinal tissue. But before the current study, little had been known about long-term shedding, especially in those who have mild COVID. Most studies of viral shedding have been with severe COVID cases.

The authors noted that most studies of this kind are cross-sectional. The few other longitudinal studies have focused on early time points just after diagnosis.

Senior author Ami S. Bhatt, MD, associate professor in the departments of medicine and hematology at Stanford University, said in an interview that, though the viral genetic material in the feces lingers, on the basis of available evidence, it is highly unlikely to be contagious in most cases.

She said that understanding the dynamics of fecal shedding of SARS-CoV-2 genetic material will help interpret wastewater-based studies that are trying to determine population prevalence of the virus.

“While we don’t know the exact clinical importance of the longer-term shedding of SARS-CoV-2 in individuals with COVID-19, some have speculated that those who have long-term shedding of SARS-CoV-2 may have ongoing infections that might benefit from treatment,” she said.

“Our data support the idea that the long-term GI-related symptoms in some people might be the consequence of an ongoing infection in the GI tract, even after the respiratory infection has cleared,” Dr. Bhatt said.

“Alternatively, the presence of ongoing viral genetic material in the gut might be a trigger for the immune system to continually be active against the virus, and our immune system reaction may be the reason for long COVID–type symptoms,” she added. “This area is ripe for additional studies.”

Dr. Bhatt and colleagues will continue studying viral shedding in fecal samples as part of the nationwide RECOVER Initiative.

When reached for comment, David A. Johnson, MD, professor of medicine and chief of gastroenterology, Eastern Virginia Medical School, Norfolk, said in an interview that previous studies have indicated that the virus may be detected in the stool for a month or more and for about 2 weeks on average. Whether the virus is infectious has been in question.

But it’s not so much that the virus is infectious in the GI tract and causing symptoms, he said. Rather, there are biomic changes related to COVID, including a loss of diversity in the gut bacteria, which disrupts the balance.

“This may actually in some way predispose some patients to impaired clearance of their symptoms,” Dr. Johnson explained. “There seems to be a growing recognition that this entity called long-haul COVID may be related to specific bacterial disruptions, and the more rapidly you can resolve these disruptions, the less likely you are to continue with long-haul symptoms.”

He said that, among people who have mild COVID, the virus typically clears and gut bacteria return to normal. With severe or persistent illness, gut dysbiosis persists, he said.

“People need to be aware that the GI tract is involved in a sizable percent of patients with COVID,” Dr. Johnson said. “The GI-tract testing may reflect that the virus is there, but persistence of the detectable test positivity is very unlikely to reflect active virus.”

The authors noted that they collected only six samples from the participants over the 10-month study period.

“Follow-up studies with more frequent sampling, especially in the first 2 months after diagnosis, may help build a more nuanced model of decline of fecal viral RNA concentration over time,” they wrote.

The study was supported by a Stanford ChemH-IMA grant, fellowships from the AACR and the National Science Foundation, and the National Institutes of Health. The authors and Dr. Johnson reported no relevant financial relationships. Dr. Johnson is a regular contributor to this news organization.

A version of this article first appeared on Medscape.com.

New data present further evidence that SARS-CoV-2 infection can settle in the gastrointestinal tract and that it can persist long after the infection has cleared the lungs.

Infection of the GI tract may figure prominently in long COVID, the study authors suggested.

Led by Aravind Natarajan, PhD, with the departments of genetics and medicine at Stanford (Calif.) University, they analyzed fecal RNA shedding up to 10 months after a COVID-19 diagnosis in 673 stool samples from 113 patients with mild to moderate disease.

They found that, in the week after diagnosis, COVID RNA remnants were present in the stool of approximately half (49.2%) of the patients. Seven months later, about 4% of them shed fecal viral RNA.

The authors noted that there was no ongoing SARS-CoV-2 RNA shedding in respiratory samples of patients at the 4-month mark.

Using self-reported symptoms regularly collected by questionnaire, they also found a correlation of long-term fecal shedding of SARS-CoV-2 RNA with abdominal pain, nausea, and vomiting.

The findings were published online in Med.
 

Implications of long-term viral shedding

Previous studies have found SARS-CoV-2 RNA in respiratory and fecal samples and have documented viral replication in lung and intestinal tissue. But before the current study, little had been known about long-term shedding, especially in those who have mild COVID. Most studies of viral shedding have been with severe COVID cases.

The authors noted that most studies of this kind are cross-sectional. The few other longitudinal studies have focused on early time points just after diagnosis.

Senior author Ami S. Bhatt, MD, associate professor in the departments of medicine and hematology at Stanford University, said in an interview that, though the viral genetic material in the feces lingers, on the basis of available evidence, it is highly unlikely to be contagious in most cases.

She said that understanding the dynamics of fecal shedding of SARS-CoV-2 genetic material will help interpret wastewater-based studies that are trying to determine population prevalence of the virus.

“While we don’t know the exact clinical importance of the longer-term shedding of SARS-CoV-2 in individuals with COVID-19, some have speculated that those who have long-term shedding of SARS-CoV-2 may have ongoing infections that might benefit from treatment,” she said.

“Our data support the idea that the long-term GI-related symptoms in some people might be the consequence of an ongoing infection in the GI tract, even after the respiratory infection has cleared,” Dr. Bhatt said.

“Alternatively, the presence of ongoing viral genetic material in the gut might be a trigger for the immune system to continually be active against the virus, and our immune system reaction may be the reason for long COVID–type symptoms,” she added. “This area is ripe for additional studies.”

Dr. Bhatt and colleagues will continue studying viral shedding in fecal samples as part of the nationwide RECOVER Initiative.

When reached for comment, David A. Johnson, MD, professor of medicine and chief of gastroenterology, Eastern Virginia Medical School, Norfolk, said in an interview that previous studies have indicated that the virus may be detected in the stool for a month or more and for about 2 weeks on average. Whether the virus is infectious has been in question.

But it’s not so much that the virus is infectious in the GI tract and causing symptoms, he said. Rather, there are biomic changes related to COVID, including a loss of diversity in the gut bacteria, which disrupts the balance.

“This may actually in some way predispose some patients to impaired clearance of their symptoms,” Dr. Johnson explained. “There seems to be a growing recognition that this entity called long-haul COVID may be related to specific bacterial disruptions, and the more rapidly you can resolve these disruptions, the less likely you are to continue with long-haul symptoms.”

He said that, among people who have mild COVID, the virus typically clears and gut bacteria return to normal. With severe or persistent illness, gut dysbiosis persists, he said.

“People need to be aware that the GI tract is involved in a sizable percent of patients with COVID,” Dr. Johnson said. “The GI-tract testing may reflect that the virus is there, but persistence of the detectable test positivity is very unlikely to reflect active virus.”

The authors noted that they collected only six samples from the participants over the 10-month study period.

“Follow-up studies with more frequent sampling, especially in the first 2 months after diagnosis, may help build a more nuanced model of decline of fecal viral RNA concentration over time,” they wrote.

The study was supported by a Stanford ChemH-IMA grant, fellowships from the AACR and the National Science Foundation, and the National Institutes of Health. The authors and Dr. Johnson reported no relevant financial relationships. Dr. Johnson is a regular contributor to this news organization.

A version of this article first appeared on Medscape.com.

New data present further evidence that SARS-CoV-2 infection can settle in the gastrointestinal tract and that it can persist long after the infection has cleared the lungs.

Infection of the GI tract may figure prominently in long COVID, the study authors suggested.

Led by Aravind Natarajan, PhD, with the departments of genetics and medicine at Stanford (Calif.) University, they analyzed fecal RNA shedding up to 10 months after a COVID-19 diagnosis in 673 stool samples from 113 patients with mild to moderate disease.

They found that, in the week after diagnosis, COVID RNA remnants were present in the stool of approximately half (49.2%) of the patients. Seven months later, about 4% of them shed fecal viral RNA.

The authors noted that there was no ongoing SARS-CoV-2 RNA shedding in respiratory samples of patients at the 4-month mark.

Using self-reported symptoms regularly collected by questionnaire, they also found a correlation of long-term fecal shedding of SARS-CoV-2 RNA with abdominal pain, nausea, and vomiting.

The findings were published online in Med.
 

Implications of long-term viral shedding

Previous studies have found SARS-CoV-2 RNA in respiratory and fecal samples and have documented viral replication in lung and intestinal tissue. But before the current study, little had been known about long-term shedding, especially in those who have mild COVID. Most studies of viral shedding have been with severe COVID cases.

The authors noted that most studies of this kind are cross-sectional. The few other longitudinal studies have focused on early time points just after diagnosis.

Senior author Ami S. Bhatt, MD, associate professor in the departments of medicine and hematology at Stanford University, said in an interview that, though the viral genetic material in the feces lingers, on the basis of available evidence, it is highly unlikely to be contagious in most cases.

She said that understanding the dynamics of fecal shedding of SARS-CoV-2 genetic material will help interpret wastewater-based studies that are trying to determine population prevalence of the virus.

“While we don’t know the exact clinical importance of the longer-term shedding of SARS-CoV-2 in individuals with COVID-19, some have speculated that those who have long-term shedding of SARS-CoV-2 may have ongoing infections that might benefit from treatment,” she said.

“Our data support the idea that the long-term GI-related symptoms in some people might be the consequence of an ongoing infection in the GI tract, even after the respiratory infection has cleared,” Dr. Bhatt said.

“Alternatively, the presence of ongoing viral genetic material in the gut might be a trigger for the immune system to continually be active against the virus, and our immune system reaction may be the reason for long COVID–type symptoms,” she added. “This area is ripe for additional studies.”

Dr. Bhatt and colleagues will continue studying viral shedding in fecal samples as part of the nationwide RECOVER Initiative.

When reached for comment, David A. Johnson, MD, professor of medicine and chief of gastroenterology, Eastern Virginia Medical School, Norfolk, said in an interview that previous studies have indicated that the virus may be detected in the stool for a month or more and for about 2 weeks on average. Whether the virus is infectious has been in question.

But it’s not so much that the virus is infectious in the GI tract and causing symptoms, he said. Rather, there are biomic changes related to COVID, including a loss of diversity in the gut bacteria, which disrupts the balance.

“This may actually in some way predispose some patients to impaired clearance of their symptoms,” Dr. Johnson explained. “There seems to be a growing recognition that this entity called long-haul COVID may be related to specific bacterial disruptions, and the more rapidly you can resolve these disruptions, the less likely you are to continue with long-haul symptoms.”

He said that, among people who have mild COVID, the virus typically clears and gut bacteria return to normal. With severe or persistent illness, gut dysbiosis persists, he said.

“People need to be aware that the GI tract is involved in a sizable percent of patients with COVID,” Dr. Johnson said. “The GI-tract testing may reflect that the virus is there, but persistence of the detectable test positivity is very unlikely to reflect active virus.”

The authors noted that they collected only six samples from the participants over the 10-month study period.

“Follow-up studies with more frequent sampling, especially in the first 2 months after diagnosis, may help build a more nuanced model of decline of fecal viral RNA concentration over time,” they wrote.

The study was supported by a Stanford ChemH-IMA grant, fellowships from the AACR and the National Science Foundation, and the National Institutes of Health. The authors and Dr. Johnson reported no relevant financial relationships. Dr. Johnson is a regular contributor to this news organization.

A version of this article first appeared on Medscape.com.

Genetically modified mosquitoes released in the United States appear to have passed an early test that suggests they might one day help reduce the population of insects that transmit infectious diseases.

As part of the test, scientists released nearly 5 million genetically engineered male Aedes aegypti mosquitoes over the course of 7 months in the Florida Keys.

Male mosquitoes don’t bite people, and these were also modified so they would transmit a gene to female offspring that causes them to die before they can reproduce. In theory, this means the population of A. aegypti mosquitoes would die off over time, so they wouldn’t spread diseases any more.

The goal of this pilot project in Florida was to see if these genetically modified male mosquitoes could successfully mate with females in the wild, and to confirm whether their female offspring would indeed die before they could reproduce. On both counts, the experiment was a success, Oxitec, the biotechnology company developing these engineered A. aegypti mosquitoes, said in a webinar.
 

More testing in Florida and California

Based on the results from this preliminary research, the Environmental Protection Agency has approved additional pilot projects in Florida and California, the company said in a statement.

“Given the growing health threat this mosquito poses across the U.S., we’re working to make this technology available and accessible,” Grey Frandsen, Oxitec’s chief executive, said in the statement. “These pilot programs, wherein we can demonstrate the technology’s effectiveness in different climate settings, will play an important role in doing so.”

A. aegypti mosquitoes can spread several serious infectious diseases to humans, including dengue, Zika, yellow fever and chikungunya, according to the Centers for Disease Control and Prevention.

Preliminary tests of the genetically modified mosquitoes weren’t designed to determine whether these engineered insects might stop the spread of these diseases. The goal of the initial tests was simply to see how reproduction played out once the genetically modified males were released.

The genetically engineered males successfully mated with females in the wild, the company reports. Scientists collected more than 22,000 eggs laid by these females from traps set out around the community in spots like flowerpots and trash cans.

In the lab, researchers confirmed that the female offspring from these pairings inherited a lethal gene designed to cause their death before adulthood. The lethal gene was transmitted to female offspring across multiple generations, scientists also found.

Many more trials would be needed before these genetically modified mosquitoes could be released in the wild on a larger scale – particularly because the tests done so far haven’t demonstrated that these engineered bugs can prevent the spread of infectious disease.

Releasing genetically modified A. aegypti mosquitoes into the wild won’t reduce the need for pesticides because most mosquitoes in the United States aren’t from this species.

A version of this article first appeared on WebMD.com.

Genetically modified mosquitoes released in the United States appear to have passed an early test that suggests they might one day help reduce the population of insects that transmit infectious diseases.

As part of the test, scientists released nearly 5 million genetically engineered male Aedes aegypti mosquitoes over the course of 7 months in the Florida Keys.

Male mosquitoes don’t bite people, and these were also modified so they would transmit a gene to female offspring that causes them to die before they can reproduce. In theory, this means the population of A. aegypti mosquitoes would die off over time, so they wouldn’t spread diseases any more.

The goal of this pilot project in Florida was to see if these genetically modified male mosquitoes could successfully mate with females in the wild, and to confirm whether their female offspring would indeed die before they could reproduce. On both counts, the experiment was a success, Oxitec, the biotechnology company developing these engineered A. aegypti mosquitoes, said in a webinar.
 

More testing in Florida and California

Based on the results from this preliminary research, the Environmental Protection Agency has approved additional pilot projects in Florida and California, the company said in a statement.

“Given the growing health threat this mosquito poses across the U.S., we’re working to make this technology available and accessible,” Grey Frandsen, Oxitec’s chief executive, said in the statement. “These pilot programs, wherein we can demonstrate the technology’s effectiveness in different climate settings, will play an important role in doing so.”

A. aegypti mosquitoes can spread several serious infectious diseases to humans, including dengue, Zika, yellow fever and chikungunya, according to the Centers for Disease Control and Prevention.

Preliminary tests of the genetically modified mosquitoes weren’t designed to determine whether these engineered insects might stop the spread of these diseases. The goal of the initial tests was simply to see how reproduction played out once the genetically modified males were released.

The genetically engineered males successfully mated with females in the wild, the company reports. Scientists collected more than 22,000 eggs laid by these females from traps set out around the community in spots like flowerpots and trash cans.

In the lab, researchers confirmed that the female offspring from these pairings inherited a lethal gene designed to cause their death before adulthood. The lethal gene was transmitted to female offspring across multiple generations, scientists also found.

Many more trials would be needed before these genetically modified mosquitoes could be released in the wild on a larger scale – particularly because the tests done so far haven’t demonstrated that these engineered bugs can prevent the spread of infectious disease.

Releasing genetically modified A. aegypti mosquitoes into the wild won’t reduce the need for pesticides because most mosquitoes in the United States aren’t from this species.

A version of this article first appeared on WebMD.com.

Genetically modified mosquitoes released in the United States appear to have passed an early test that suggests they might one day help reduce the population of insects that transmit infectious diseases.

As part of the test, scientists released nearly 5 million genetically engineered male Aedes aegypti mosquitoes over the course of 7 months in the Florida Keys.

Male mosquitoes don’t bite people, and these were also modified so they would transmit a gene to female offspring that causes them to die before they can reproduce. In theory, this means the population of A. aegypti mosquitoes would die off over time, so they wouldn’t spread diseases any more.

The goal of this pilot project in Florida was to see if these genetically modified male mosquitoes could successfully mate with females in the wild, and to confirm whether their female offspring would indeed die before they could reproduce. On both counts, the experiment was a success, Oxitec, the biotechnology company developing these engineered A. aegypti mosquitoes, said in a webinar.
 

More testing in Florida and California

Based on the results from this preliminary research, the Environmental Protection Agency has approved additional pilot projects in Florida and California, the company said in a statement.

“Given the growing health threat this mosquito poses across the U.S., we’re working to make this technology available and accessible,” Grey Frandsen, Oxitec’s chief executive, said in the statement. “These pilot programs, wherein we can demonstrate the technology’s effectiveness in different climate settings, will play an important role in doing so.”

A. aegypti mosquitoes can spread several serious infectious diseases to humans, including dengue, Zika, yellow fever and chikungunya, according to the Centers for Disease Control and Prevention.

Preliminary tests of the genetically modified mosquitoes weren’t designed to determine whether these engineered insects might stop the spread of these diseases. The goal of the initial tests was simply to see how reproduction played out once the genetically modified males were released.

The genetically engineered males successfully mated with females in the wild, the company reports. Scientists collected more than 22,000 eggs laid by these females from traps set out around the community in spots like flowerpots and trash cans.

In the lab, researchers confirmed that the female offspring from these pairings inherited a lethal gene designed to cause their death before adulthood. The lethal gene was transmitted to female offspring across multiple generations, scientists also found.

Many more trials would be needed before these genetically modified mosquitoes could be released in the wild on a larger scale – particularly because the tests done so far haven’t demonstrated that these engineered bugs can prevent the spread of infectious disease.

Releasing genetically modified A. aegypti mosquitoes into the wild won’t reduce the need for pesticides because most mosquitoes in the United States aren’t from this species.

A version of this article first appeared on WebMD.com.

New data present further evidence that SARS-CoV-2 infection can settle in the gastrointestinal (GI) tract and that it can persist long after the infection has cleared the lungs.

Infection of the GI tract may figure prominently in long COVID, the study authors suggest.

Led by Aravind Natarajan, PhD, with the departments of genetics and medicine at Stanford (Calif.) University, they analyzed fecal RNA shedding up to 10 months after a COVID-19 diagnosis in 673 stool samples from 113 patients with mild to moderate disease.

They found that in the week after diagnosis, COVID RNA remnants were present in the stool of approximately half (49.2%) of the patients. Seven months later, about 4% of them shed fecal viral RNA.

The authors note that there was no ongoing SARS-CoV-2 RNA shedding in respiratory samples of patients at the 4-month mark.

Using self-reported symptoms regularly collected by questionnaire, they also found a correlation of long-term fecal shedding of SARS-CoV-2 RNA with abdominal pain, nausea, and vomiting.

The findings were published online in Med.
 

Implications of long-term viral shedding

Previous studies have found SARS-CoV-2 RNA in respiratory and fecal samples and have documented viral replication in lung and intestinal tissue.

But before the current study, little had been known about long-term shedding, especially in those who have mild COVID. Most studies of viral shedding have been with severe COVID cases.

The authors note that most studies of this kind are cross-sectional. The few other longitudinal studies have focused on early time points just after diagnosis.

Senior author Ami S. Bhatt, MD, associate professor in the departments of medicine and hematology at Stanford, told this news organization that though the viral genetic material in the feces lingers, on the basis of available evidence, it is highly unlikely to be contagious in most cases.

She said that understanding the dynamics of fecal shedding of SARS-CoV-2 genetic material will help interpret wastewater-based studies that are trying to determine population prevalence of the virus.

“While we don’t know the exact clinical importance of the longer-term shedding of SARS-CoV-2 in individuals with COVID-19, some have speculated that those who have long-term shedding of SARS-CoV-2 may have ongoing infections that might benefit from treatment,” she said.

“Our data support the idea that the long-term GI-related symptoms in some people might be the consequence of an ongoing infection in the GI tract, even after the respiratory infection has cleared,” Dr. Bhatt said.

“Alternatively, the presence of ongoing viral genetic material in the gut might be a trigger for the immune system to continually be active against the virus, and our immune system reaction may be the reason for long-COVID type symptoms,” she added. “This area is ripe for additional studies.”

Dr. Bhatt and colleagues will continue studying viral shedding in fecal samples as part of the nationwide RECOVER Initiative.

When reached for comment, David A. Johnson, MD, professor of medicine and chief of gastroenterology, Eastern Virginia Medical School, Norfolk, said in an interview that previous studies have indicated that the virus may be detected in the stool for a month or more and for about 2 weeks on average. Whether the virus is infectious has been in question.

But it’s not so much that the virus is infectious in the GI tract and causing symptoms, he said. Rather, there are biomic changes related to COVID, including a loss of diversity in the gut bacteria, which disrupts the balance.

“This may actually in some way predispose some patients to impaired clearance of their symptoms,” Dr. Johnson explained. “There seems to be a growing recognition that this entity called long-haul COVID may be related to specific bacterial disruptions, and the more rapidly you can resolve these disruptions, the less likely you are to continue with long-haul symptoms.”

He said that among people who have mild COVID, the virus typically clears and gut bacteria return to normal. With severe or persistent illness, gut dysbiosis persists, he said.

“People need to be aware that the GI tract is involved in a sizable percent of patients with COVID,” Dr. Johnson said. “The GI-tract testing may reflect that the virus is there, but persistence of the detectable test positivity is very unlikely to reflect active virus.”

The authors note in this study that they collected only six samples from the participants over the 10-month period.

“Follow-up studies with more frequent sampling, especially in the first 2 months after diagnosis, may help build a more nuanced model of decline of fecal viral RNA concentration over time,” they write.

The study was supported by a Stanford ChemH-IMA grant, fellowships from the AACR and the National Science Foundation, and the National Institutes of Health. The authors and Dr. Johnson report no relevant financial relationships. Dr. Johnson is a regular contributor to Medscape.

A version of this article first appeared to Medscape.com.

New data present further evidence that SARS-CoV-2 infection can settle in the gastrointestinal (GI) tract and that it can persist long after the infection has cleared the lungs.

Infection of the GI tract may figure prominently in long COVID, the study authors suggest.

Led by Aravind Natarajan, PhD, with the departments of genetics and medicine at Stanford (Calif.) University, they analyzed fecal RNA shedding up to 10 months after a COVID-19 diagnosis in 673 stool samples from 113 patients with mild to moderate disease.

They found that in the week after diagnosis, COVID RNA remnants were present in the stool of approximately half (49.2%) of the patients. Seven months later, about 4% of them shed fecal viral RNA.

The authors note that there was no ongoing SARS-CoV-2 RNA shedding in respiratory samples of patients at the 4-month mark.

Using self-reported symptoms regularly collected by questionnaire, they also found a correlation of long-term fecal shedding of SARS-CoV-2 RNA with abdominal pain, nausea, and vomiting.

The findings were published online in Med.
 

Implications of long-term viral shedding

Previous studies have found SARS-CoV-2 RNA in respiratory and fecal samples and have documented viral replication in lung and intestinal tissue.

But before the current study, little had been known about long-term shedding, especially in those who have mild COVID. Most studies of viral shedding have been with severe COVID cases.

The authors note that most studies of this kind are cross-sectional. The few other longitudinal studies have focused on early time points just after diagnosis.

Senior author Ami S. Bhatt, MD, associate professor in the departments of medicine and hematology at Stanford, told this news organization that though the viral genetic material in the feces lingers, on the basis of available evidence, it is highly unlikely to be contagious in most cases.

She said that understanding the dynamics of fecal shedding of SARS-CoV-2 genetic material will help interpret wastewater-based studies that are trying to determine population prevalence of the virus.

“While we don’t know the exact clinical importance of the longer-term shedding of SARS-CoV-2 in individuals with COVID-19, some have speculated that those who have long-term shedding of SARS-CoV-2 may have ongoing infections that might benefit from treatment,” she said.

“Our data support the idea that the long-term GI-related symptoms in some people might be the consequence of an ongoing infection in the GI tract, even after the respiratory infection has cleared,” Dr. Bhatt said.

“Alternatively, the presence of ongoing viral genetic material in the gut might be a trigger for the immune system to continually be active against the virus, and our immune system reaction may be the reason for long-COVID type symptoms,” she added. “This area is ripe for additional studies.”

Dr. Bhatt and colleagues will continue studying viral shedding in fecal samples as part of the nationwide RECOVER Initiative.

When reached for comment, David A. Johnson, MD, professor of medicine and chief of gastroenterology, Eastern Virginia Medical School, Norfolk, said in an interview that previous studies have indicated that the virus may be detected in the stool for a month or more and for about 2 weeks on average. Whether the virus is infectious has been in question.

But it’s not so much that the virus is infectious in the GI tract and causing symptoms, he said. Rather, there are biomic changes related to COVID, including a loss of diversity in the gut bacteria, which disrupts the balance.

“This may actually in some way predispose some patients to impaired clearance of their symptoms,” Dr. Johnson explained. “There seems to be a growing recognition that this entity called long-haul COVID may be related to specific bacterial disruptions, and the more rapidly you can resolve these disruptions, the less likely you are to continue with long-haul symptoms.”

He said that among people who have mild COVID, the virus typically clears and gut bacteria return to normal. With severe or persistent illness, gut dysbiosis persists, he said.

“People need to be aware that the GI tract is involved in a sizable percent of patients with COVID,” Dr. Johnson said. “The GI-tract testing may reflect that the virus is there, but persistence of the detectable test positivity is very unlikely to reflect active virus.”

The authors note in this study that they collected only six samples from the participants over the 10-month period.

“Follow-up studies with more frequent sampling, especially in the first 2 months after diagnosis, may help build a more nuanced model of decline of fecal viral RNA concentration over time,” they write.

The study was supported by a Stanford ChemH-IMA grant, fellowships from the AACR and the National Science Foundation, and the National Institutes of Health. The authors and Dr. Johnson report no relevant financial relationships. Dr. Johnson is a regular contributor to Medscape.

A version of this article first appeared to Medscape.com.

New data present further evidence that SARS-CoV-2 infection can settle in the gastrointestinal (GI) tract and that it can persist long after the infection has cleared the lungs.

Infection of the GI tract may figure prominently in long COVID, the study authors suggest.

Led by Aravind Natarajan, PhD, with the departments of genetics and medicine at Stanford (Calif.) University, they analyzed fecal RNA shedding up to 10 months after a COVID-19 diagnosis in 673 stool samples from 113 patients with mild to moderate disease.

They found that in the week after diagnosis, COVID RNA remnants were present in the stool of approximately half (49.2%) of the patients. Seven months later, about 4% of them shed fecal viral RNA.

The authors note that there was no ongoing SARS-CoV-2 RNA shedding in respiratory samples of patients at the 4-month mark.

Using self-reported symptoms regularly collected by questionnaire, they also found a correlation of long-term fecal shedding of SARS-CoV-2 RNA with abdominal pain, nausea, and vomiting.

The findings were published online in Med.
 

Implications of long-term viral shedding

Previous studies have found SARS-CoV-2 RNA in respiratory and fecal samples and have documented viral replication in lung and intestinal tissue.

But before the current study, little had been known about long-term shedding, especially in those who have mild COVID. Most studies of viral shedding have been with severe COVID cases.

The authors note that most studies of this kind are cross-sectional. The few other longitudinal studies have focused on early time points just after diagnosis.

Senior author Ami S. Bhatt, MD, associate professor in the departments of medicine and hematology at Stanford, told this news organization that though the viral genetic material in the feces lingers, on the basis of available evidence, it is highly unlikely to be contagious in most cases.

She said that understanding the dynamics of fecal shedding of SARS-CoV-2 genetic material will help interpret wastewater-based studies that are trying to determine population prevalence of the virus.

“While we don’t know the exact clinical importance of the longer-term shedding of SARS-CoV-2 in individuals with COVID-19, some have speculated that those who have long-term shedding of SARS-CoV-2 may have ongoing infections that might benefit from treatment,” she said.

“Our data support the idea that the long-term GI-related symptoms in some people might be the consequence of an ongoing infection in the GI tract, even after the respiratory infection has cleared,” Dr. Bhatt said.

“Alternatively, the presence of ongoing viral genetic material in the gut might be a trigger for the immune system to continually be active against the virus, and our immune system reaction may be the reason for long-COVID type symptoms,” she added. “This area is ripe for additional studies.”

Dr. Bhatt and colleagues will continue studying viral shedding in fecal samples as part of the nationwide RECOVER Initiative.

When reached for comment, David A. Johnson, MD, professor of medicine and chief of gastroenterology, Eastern Virginia Medical School, Norfolk, said in an interview that previous studies have indicated that the virus may be detected in the stool for a month or more and for about 2 weeks on average. Whether the virus is infectious has been in question.

But it’s not so much that the virus is infectious in the GI tract and causing symptoms, he said. Rather, there are biomic changes related to COVID, including a loss of diversity in the gut bacteria, which disrupts the balance.

“This may actually in some way predispose some patients to impaired clearance of their symptoms,” Dr. Johnson explained. “There seems to be a growing recognition that this entity called long-haul COVID may be related to specific bacterial disruptions, and the more rapidly you can resolve these disruptions, the less likely you are to continue with long-haul symptoms.”

He said that among people who have mild COVID, the virus typically clears and gut bacteria return to normal. With severe or persistent illness, gut dysbiosis persists, he said.

“People need to be aware that the GI tract is involved in a sizable percent of patients with COVID,” Dr. Johnson said. “The GI-tract testing may reflect that the virus is there, but persistence of the detectable test positivity is very unlikely to reflect active virus.”

The authors note in this study that they collected only six samples from the participants over the 10-month period.

“Follow-up studies with more frequent sampling, especially in the first 2 months after diagnosis, may help build a more nuanced model of decline of fecal viral RNA concentration over time,” they write.

The study was supported by a Stanford ChemH-IMA grant, fellowships from the AACR and the National Science Foundation, and the National Institutes of Health. The authors and Dr. Johnson report no relevant financial relationships. Dr. Johnson is a regular contributor to Medscape.

A version of this article first appeared to Medscape.com.

The current sustained increase in COVID-19 has brought the total number of cases in children to over 13 million since the start of the pandemic, according to the American Academy of Pediatrics and the Children’s Hospital Association.

The latest weekly count – 62,467 reported for the week ending May 5 – was 17.4% higher than the previous week and marks four consecutive increases since early April, when cases dropped to their lowest point since last summer. The cumulative number of cases in children is 13,052,988, which accounts for 19.0% of all cases reported in the United States, the AAP and CHA said in their weekly COVID-19 report.

Other measures of incidence show the same steady rise. The rate of new admissions of children aged 0-17 with confirmed COVID-19, which had dipped as low as 0.13 per 100,000 population on April 11, was up to 0.19 per 100,000 on May 6, and the 7-day average for total admissions was 136 per day for May 1-7, compared with 118 for the last week of April, according to the Centers for Disease Control and Prevention.

At the state level, new admission rates for May 6 show wide variation, even regionally. Rhode Island came in with a 0.00 per 100,000 on that day, while Vermont recorded 0.88 admissions per 100,000, the highest of any state and lower only than the District of Columbia’s 1.23 per 100,000. Connecticut (0.45) and Massachusetts (0.33) also were in the highest group (see map), while Maine was in the lowest, CDC data show.

Nationally, emergency department visits also have been rising over the last month or so. Children aged 0-11 years, who were down to a 7-day average of 0.5% of ED visits with diagnosed COVID-19 in early April, saw that number rise to 1.4% on May 5. Children aged 12-15 years went from a rate of 0.3% in late March to the current 1.2%, as did 16- to 17-year-olds, the CDC said on its COVID Data Tracker.

The vaccination effort, meanwhile, continues to lose steam, at least among children who are currently eligible. Initial vaccinations in those aged 5-11 slipped to their lowest-ever 1-week total, 47,000 for April 28 to May 4, while children aged 16-17 continued a long-term slide that has the weekly count down to just 29,000, the AAP said in its weekly vaccination report.

Here’s how those latest recipients changed the populations of vaccinated children in the last week: 35.4% of all 5- to 11-year-olds had received at least one dose as of May 4, compared with 35.3% on April 27, with increases from 67.4% to 67.5% for 12- to 15-year-olds and 72.7% to 72.8% among those aged 16-17, the CDC reported.
 

The current sustained increase in COVID-19 has brought the total number of cases in children to over 13 million since the start of the pandemic, according to the American Academy of Pediatrics and the Children’s Hospital Association.

The latest weekly count – 62,467 reported for the week ending May 5 – was 17.4% higher than the previous week and marks four consecutive increases since early April, when cases dropped to their lowest point since last summer. The cumulative number of cases in children is 13,052,988, which accounts for 19.0% of all cases reported in the United States, the AAP and CHA said in their weekly COVID-19 report.

Other measures of incidence show the same steady rise. The rate of new admissions of children aged 0-17 with confirmed COVID-19, which had dipped as low as 0.13 per 100,000 population on April 11, was up to 0.19 per 100,000 on May 6, and the 7-day average for total admissions was 136 per day for May 1-7, compared with 118 for the last week of April, according to the Centers for Disease Control and Prevention.

At the state level, new admission rates for May 6 show wide variation, even regionally. Rhode Island came in with a 0.00 per 100,000 on that day, while Vermont recorded 0.88 admissions per 100,000, the highest of any state and lower only than the District of Columbia’s 1.23 per 100,000. Connecticut (0.45) and Massachusetts (0.33) also were in the highest group (see map), while Maine was in the lowest, CDC data show.

Nationally, emergency department visits also have been rising over the last month or so. Children aged 0-11 years, who were down to a 7-day average of 0.5% of ED visits with diagnosed COVID-19 in early April, saw that number rise to 1.4% on May 5. Children aged 12-15 years went from a rate of 0.3% in late March to the current 1.2%, as did 16- to 17-year-olds, the CDC said on its COVID Data Tracker.

The vaccination effort, meanwhile, continues to lose steam, at least among children who are currently eligible. Initial vaccinations in those aged 5-11 slipped to their lowest-ever 1-week total, 47,000 for April 28 to May 4, while children aged 16-17 continued a long-term slide that has the weekly count down to just 29,000, the AAP said in its weekly vaccination report.

Here’s how those latest recipients changed the populations of vaccinated children in the last week: 35.4% of all 5- to 11-year-olds had received at least one dose as of May 4, compared with 35.3% on April 27, with increases from 67.4% to 67.5% for 12- to 15-year-olds and 72.7% to 72.8% among those aged 16-17, the CDC reported.
 

The current sustained increase in COVID-19 has brought the total number of cases in children to over 13 million since the start of the pandemic, according to the American Academy of Pediatrics and the Children’s Hospital Association.

The latest weekly count – 62,467 reported for the week ending May 5 – was 17.4% higher than the previous week and marks four consecutive increases since early April, when cases dropped to their lowest point since last summer. The cumulative number of cases in children is 13,052,988, which accounts for 19.0% of all cases reported in the United States, the AAP and CHA said in their weekly COVID-19 report.

Other measures of incidence show the same steady rise. The rate of new admissions of children aged 0-17 with confirmed COVID-19, which had dipped as low as 0.13 per 100,000 population on April 11, was up to 0.19 per 100,000 on May 6, and the 7-day average for total admissions was 136 per day for May 1-7, compared with 118 for the last week of April, according to the Centers for Disease Control and Prevention.

At the state level, new admission rates for May 6 show wide variation, even regionally. Rhode Island came in with a 0.00 per 100,000 on that day, while Vermont recorded 0.88 admissions per 100,000, the highest of any state and lower only than the District of Columbia’s 1.23 per 100,000. Connecticut (0.45) and Massachusetts (0.33) also were in the highest group (see map), while Maine was in the lowest, CDC data show.

Nationally, emergency department visits also have been rising over the last month or so. Children aged 0-11 years, who were down to a 7-day average of 0.5% of ED visits with diagnosed COVID-19 in early April, saw that number rise to 1.4% on May 5. Children aged 12-15 years went from a rate of 0.3% in late March to the current 1.2%, as did 16- to 17-year-olds, the CDC said on its COVID Data Tracker.

The vaccination effort, meanwhile, continues to lose steam, at least among children who are currently eligible. Initial vaccinations in those aged 5-11 slipped to their lowest-ever 1-week total, 47,000 for April 28 to May 4, while children aged 16-17 continued a long-term slide that has the weekly count down to just 29,000, the AAP said in its weekly vaccination report.

Here’s how those latest recipients changed the populations of vaccinated children in the last week: 35.4% of all 5- to 11-year-olds had received at least one dose as of May 4, compared with 35.3% on April 27, with increases from 67.4% to 67.5% for 12- to 15-year-olds and 72.7% to 72.8% among those aged 16-17, the CDC reported.
 

People who are not vaccinated against a respiratory virus such as SARS-CoV-2 present a disproportionate infectious risk to those who are vaccinated, according to a mathematical modeling study.

The study, which simulated patterns of infection among vaccinated and unvaccinated populations, showed that, as the populations mixed less, attack rates decreased among vaccinated people (from 15% to 10%) and increased among unvaccinated people (from 62% to 79%). The unvaccinated increasingly became the source of infection, however.

“When the vaccinated and unvaccinated mix, indirect protection is conferred upon the unvaccinated by the buffering effect of vaccinated individuals, and by contrast, risk in the vaccinated goes up,” lead author David Fisman, MD, professor of epidemiology at the University of Toronto, told this news organization.

As the groups mix less and less, the size of the epidemic increases among the unvaccinated and decreases among the vaccinated. “But the impact of the unvaccinated on risk in the vaccinated is disproportionate to the numbers of contacts between the two groups,” said Dr. Fisman.

The study was published online in the Canadian Medical Association Journal.


 

Relative contributions to risk

The researchers used a model of a respiratory viral disease “similar to SARS-CoV-2 infection with Delta variant.” They included reproduction values to capture the dynamics of the Omicron variant, which was emerging at the time. In the study, vaccines ranged in effectiveness from 40% to 80%. The study incorporated various levels of mixing between a partially vaccinated and an unvaccinated population. The mixing ranged from random mixing to like-with-like mixing (“assortativity”). There were three possible “compartments” of people in the model: those considered susceptible to infection, those considered infected and infectious, and those considered immune because of recovery.

The model showed that, as mixing between the vaccinated and the unvaccinated populations increased, case numbers rose, “with cases in the unvaccinated subpopulation accounting for a substantial proportion of infections.” However, as mixing between the populations decreased, the final attack rate decreased among vaccinated people, but the relative “contribution of risk to vaccinated people caused by infection acquired from contact with unvaccinated people ... increased.”

When the vaccination rate was increased in the model, case numbers among the vaccinated declined “as expected, owing to indirect protective effects,” the researchers noted. But this also “further increased the relative contribution to risk in vaccinated people by those who were unvaccinated.”
 

Self-regarding risk?

The findings show that “choices made by people who forgo vaccination contribute disproportionately to risk among those who do get vaccinated,” the researchers wrote. “Although risk associated with avoiding vaccination during a virulent pandemic accrues chiefly to those who are unvaccinated, the choice of some individuals to refuse vaccination is likely to affect the health and safety of vaccinated people in a manner disproportionate to the fraction of unvaccinated people in the population.”

The fact that like-with-like mixing cannot mitigate the risk to vaccinated people “undermines the assertion that vaccine choice is best left to the individual and supports strong public actions aimed at enhancing vaccine uptake and limiting access to public spaces for unvaccinated people,” they wrote.
 

Mandates and passports

“Our model provides support for vaccine mandates and passports during epidemics, such that vaccination is required for people to take part in nonessential activities,” said Dr. Fisman. The choice to not be vaccinated against COVID-19 should not be considered “self-regarding,” he added. “Risk is self-regarding when it only impacts the person engaging in the activity. Something like smoking cigarettes (alone, without others around) creates a lot of risk over time, but if nobody is breathing your secondhand smoke, you’re only creating risk for yourself. By contrast, we regulate, in Ontario, your right to smoke in public indoor spaces such as restaurants, because once other people are around, the risk isn’t self-regarding anymore. You’re creating risk for others.”

The authors also noted that the risks created by the unvaccinated extend beyond those of infection by “creating a risk that those around them may not be able to obtain the care they need.” They recommended that considerations of equity and justice for people who do choose to be vaccinated, as well as those who choose not to be, need to be included in formulating vaccination policy.
 

Illuminating the discussion

Asked to comment on the study, Matthew Oughton, MD, assistant professor of medicine at McGill University, Montreal, said: “It is easy to dismiss a mathematical model as a series of assumptions that leads to an implausible conclusion. ... However, they can serve to illustrate and, to an extent, quantify the results of complex interactions, and this study does just that.” Dr. Oughton was not involved in the research.

During the past 2 years, the scientific press and the general press have often discussed the individual and collective effects of disease-prevention methods, including nonpharmaceutical interventions. “Models like this can help illuminate those discussions by highlighting important consequences of preventive measures,” said Dr. Oughton, who also works in the division of infectious diseases at the Jewish General Hospital, Montreal.

It’s worth noting that the authors modeled vaccine effectiveness against all infection, “rather than the generally greater and more durable effects we have seen for vaccines in prevention of severe infection,” said Dr. Oughton. He added that the authors did not include the effect of vaccination in reducing forward transmission. “Inclusion of this effect would presumably have reduced overall infectious burden in mixed populations and increased the difference between groups at lower levels of mixing between populations.”

The research was supported by a grant from the Canadian Institutes of Health Research. Dr. Fisman has served on advisory boards related to influenza and SARS-CoV-2 vaccines for Seqirus, Pfizer, AstraZeneca, and Sanofi-Pasteur Vaccines and has served as a legal expert on issues related to COVID-19 epidemiology for the Elementary Teachers Federation of Ontario and the Registered Nurses Association of Ontario. Dr. Oughton disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

People who are not vaccinated against a respiratory virus such as SARS-CoV-2 present a disproportionate infectious risk to those who are vaccinated, according to a mathematical modeling study.

The study, which simulated patterns of infection among vaccinated and unvaccinated populations, showed that, as the populations mixed less, attack rates decreased among vaccinated people (from 15% to 10%) and increased among unvaccinated people (from 62% to 79%). The unvaccinated increasingly became the source of infection, however.

“When the vaccinated and unvaccinated mix, indirect protection is conferred upon the unvaccinated by the buffering effect of vaccinated individuals, and by contrast, risk in the vaccinated goes up,” lead author David Fisman, MD, professor of epidemiology at the University of Toronto, told this news organization.

As the groups mix less and less, the size of the epidemic increases among the unvaccinated and decreases among the vaccinated. “But the impact of the unvaccinated on risk in the vaccinated is disproportionate to the numbers of contacts between the two groups,” said Dr. Fisman.

The study was published online in the Canadian Medical Association Journal.


 

Relative contributions to risk

The researchers used a model of a respiratory viral disease “similar to SARS-CoV-2 infection with Delta variant.” They included reproduction values to capture the dynamics of the Omicron variant, which was emerging at the time. In the study, vaccines ranged in effectiveness from 40% to 80%. The study incorporated various levels of mixing between a partially vaccinated and an unvaccinated population. The mixing ranged from random mixing to like-with-like mixing (“assortativity”). There were three possible “compartments” of people in the model: those considered susceptible to infection, those considered infected and infectious, and those considered immune because of recovery.

The model showed that, as mixing between the vaccinated and the unvaccinated populations increased, case numbers rose, “with cases in the unvaccinated subpopulation accounting for a substantial proportion of infections.” However, as mixing between the populations decreased, the final attack rate decreased among vaccinated people, but the relative “contribution of risk to vaccinated people caused by infection acquired from contact with unvaccinated people ... increased.”

When the vaccination rate was increased in the model, case numbers among the vaccinated declined “as expected, owing to indirect protective effects,” the researchers noted. But this also “further increased the relative contribution to risk in vaccinated people by those who were unvaccinated.”
 

Self-regarding risk?

The findings show that “choices made by people who forgo vaccination contribute disproportionately to risk among those who do get vaccinated,” the researchers wrote. “Although risk associated with avoiding vaccination during a virulent pandemic accrues chiefly to those who are unvaccinated, the choice of some individuals to refuse vaccination is likely to affect the health and safety of vaccinated people in a manner disproportionate to the fraction of unvaccinated people in the population.”

The fact that like-with-like mixing cannot mitigate the risk to vaccinated people “undermines the assertion that vaccine choice is best left to the individual and supports strong public actions aimed at enhancing vaccine uptake and limiting access to public spaces for unvaccinated people,” they wrote.
 

Mandates and passports

“Our model provides support for vaccine mandates and passports during epidemics, such that vaccination is required for people to take part in nonessential activities,” said Dr. Fisman. The choice to not be vaccinated against COVID-19 should not be considered “self-regarding,” he added. “Risk is self-regarding when it only impacts the person engaging in the activity. Something like smoking cigarettes (alone, without others around) creates a lot of risk over time, but if nobody is breathing your secondhand smoke, you’re only creating risk for yourself. By contrast, we regulate, in Ontario, your right to smoke in public indoor spaces such as restaurants, because once other people are around, the risk isn’t self-regarding anymore. You’re creating risk for others.”

The authors also noted that the risks created by the unvaccinated extend beyond those of infection by “creating a risk that those around them may not be able to obtain the care they need.” They recommended that considerations of equity and justice for people who do choose to be vaccinated, as well as those who choose not to be, need to be included in formulating vaccination policy.
 

Illuminating the discussion

Asked to comment on the study, Matthew Oughton, MD, assistant professor of medicine at McGill University, Montreal, said: “It is easy to dismiss a mathematical model as a series of assumptions that leads to an implausible conclusion. ... However, they can serve to illustrate and, to an extent, quantify the results of complex interactions, and this study does just that.” Dr. Oughton was not involved in the research.

During the past 2 years, the scientific press and the general press have often discussed the individual and collective effects of disease-prevention methods, including nonpharmaceutical interventions. “Models like this can help illuminate those discussions by highlighting important consequences of preventive measures,” said Dr. Oughton, who also works in the division of infectious diseases at the Jewish General Hospital, Montreal.

It’s worth noting that the authors modeled vaccine effectiveness against all infection, “rather than the generally greater and more durable effects we have seen for vaccines in prevention of severe infection,” said Dr. Oughton. He added that the authors did not include the effect of vaccination in reducing forward transmission. “Inclusion of this effect would presumably have reduced overall infectious burden in mixed populations and increased the difference between groups at lower levels of mixing between populations.”

The research was supported by a grant from the Canadian Institutes of Health Research. Dr. Fisman has served on advisory boards related to influenza and SARS-CoV-2 vaccines for Seqirus, Pfizer, AstraZeneca, and Sanofi-Pasteur Vaccines and has served as a legal expert on issues related to COVID-19 epidemiology for the Elementary Teachers Federation of Ontario and the Registered Nurses Association of Ontario. Dr. Oughton disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

People who are not vaccinated against a respiratory virus such as SARS-CoV-2 present a disproportionate infectious risk to those who are vaccinated, according to a mathematical modeling study.

The study, which simulated patterns of infection among vaccinated and unvaccinated populations, showed that, as the populations mixed less, attack rates decreased among vaccinated people (from 15% to 10%) and increased among unvaccinated people (from 62% to 79%). The unvaccinated increasingly became the source of infection, however.

“When the vaccinated and unvaccinated mix, indirect protection is conferred upon the unvaccinated by the buffering effect of vaccinated individuals, and by contrast, risk in the vaccinated goes up,” lead author David Fisman, MD, professor of epidemiology at the University of Toronto, told this news organization.

As the groups mix less and less, the size of the epidemic increases among the unvaccinated and decreases among the vaccinated. “But the impact of the unvaccinated on risk in the vaccinated is disproportionate to the numbers of contacts between the two groups,” said Dr. Fisman.

The study was published online in the Canadian Medical Association Journal.


 

Relative contributions to risk

The researchers used a model of a respiratory viral disease “similar to SARS-CoV-2 infection with Delta variant.” They included reproduction values to capture the dynamics of the Omicron variant, which was emerging at the time. In the study, vaccines ranged in effectiveness from 40% to 80%. The study incorporated various levels of mixing between a partially vaccinated and an unvaccinated population. The mixing ranged from random mixing to like-with-like mixing (“assortativity”). There were three possible “compartments” of people in the model: those considered susceptible to infection, those considered infected and infectious, and those considered immune because of recovery.

The model showed that, as mixing between the vaccinated and the unvaccinated populations increased, case numbers rose, “with cases in the unvaccinated subpopulation accounting for a substantial proportion of infections.” However, as mixing between the populations decreased, the final attack rate decreased among vaccinated people, but the relative “contribution of risk to vaccinated people caused by infection acquired from contact with unvaccinated people ... increased.”

When the vaccination rate was increased in the model, case numbers among the vaccinated declined “as expected, owing to indirect protective effects,” the researchers noted. But this also “further increased the relative contribution to risk in vaccinated people by those who were unvaccinated.”
 

Self-regarding risk?

The findings show that “choices made by people who forgo vaccination contribute disproportionately to risk among those who do get vaccinated,” the researchers wrote. “Although risk associated with avoiding vaccination during a virulent pandemic accrues chiefly to those who are unvaccinated, the choice of some individuals to refuse vaccination is likely to affect the health and safety of vaccinated people in a manner disproportionate to the fraction of unvaccinated people in the population.”

The fact that like-with-like mixing cannot mitigate the risk to vaccinated people “undermines the assertion that vaccine choice is best left to the individual and supports strong public actions aimed at enhancing vaccine uptake and limiting access to public spaces for unvaccinated people,” they wrote.
 

Mandates and passports

“Our model provides support for vaccine mandates and passports during epidemics, such that vaccination is required for people to take part in nonessential activities,” said Dr. Fisman. The choice to not be vaccinated against COVID-19 should not be considered “self-regarding,” he added. “Risk is self-regarding when it only impacts the person engaging in the activity. Something like smoking cigarettes (alone, without others around) creates a lot of risk over time, but if nobody is breathing your secondhand smoke, you’re only creating risk for yourself. By contrast, we regulate, in Ontario, your right to smoke in public indoor spaces such as restaurants, because once other people are around, the risk isn’t self-regarding anymore. You’re creating risk for others.”

The authors also noted that the risks created by the unvaccinated extend beyond those of infection by “creating a risk that those around them may not be able to obtain the care they need.” They recommended that considerations of equity and justice for people who do choose to be vaccinated, as well as those who choose not to be, need to be included in formulating vaccination policy.
 

Illuminating the discussion

Asked to comment on the study, Matthew Oughton, MD, assistant professor of medicine at McGill University, Montreal, said: “It is easy to dismiss a mathematical model as a series of assumptions that leads to an implausible conclusion. ... However, they can serve to illustrate and, to an extent, quantify the results of complex interactions, and this study does just that.” Dr. Oughton was not involved in the research.

During the past 2 years, the scientific press and the general press have often discussed the individual and collective effects of disease-prevention methods, including nonpharmaceutical interventions. “Models like this can help illuminate those discussions by highlighting important consequences of preventive measures,” said Dr. Oughton, who also works in the division of infectious diseases at the Jewish General Hospital, Montreal.

It’s worth noting that the authors modeled vaccine effectiveness against all infection, “rather than the generally greater and more durable effects we have seen for vaccines in prevention of severe infection,” said Dr. Oughton. He added that the authors did not include the effect of vaccination in reducing forward transmission. “Inclusion of this effect would presumably have reduced overall infectious burden in mixed populations and increased the difference between groups at lower levels of mixing between populations.”

The research was supported by a grant from the Canadian Institutes of Health Research. Dr. Fisman has served on advisory boards related to influenza and SARS-CoV-2 vaccines for Seqirus, Pfizer, AstraZeneca, and Sanofi-Pasteur Vaccines and has served as a legal expert on issues related to COVID-19 epidemiology for the Elementary Teachers Federation of Ontario and the Registered Nurses Association of Ontario. Dr. Oughton disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

The percentage of low-income pregnant mothers who received influenza and Tdap vaccinations fell sharply during the COVID-19 pandemic, especially in Black and Hispanic patients, a new study finds.

The percentage of patients who received the influenza vaccines at two Medicaid clinics in Houston dropped from 78% before the pandemic to 61% during it (adjusted odds ratio, 0.38; 95% CI, 0.26-0.53; P < .01), researchers reported at the annual clinical and scientific meeting of the American College of Obstetricians and Gynecologists. The percentage receiving the Tdap vaccine dipped from 85% to 76% (aOR, 0.56; 95% CI, 0.40-0.79; P < .01).

New York–Presbyterian/Weill Cornell Medical Center pediatrician Sallie Permar, MD, PhD, who’s familiar with the study findings, called them “alarming” and said in an interview that they should be “a call to action for providers.”

“Continuing the status quo in our routine preventative health care and clinic operations means that we are losing ground in reduction and elimination of vaccine-preventable diseases,” Dr. Permar said in an interview.

According to corresponding author Bani Ratan, MD, an ob.gyn. with the Baylor College of Medicine, Houston, there’s been little if any previous research into routine, non-COVID vaccination in pregnant women during the pandemic.

For the study, researchers retrospectively analyzed the records of 939 pregnant women who entered prenatal care before 20 weeks (462 from May–November 2019, and 477 from May–November 2020) and delivered at full term.

Among ethnic groups, non-Hispanic Blacks saw the largest decline in influenza vaccines. Among them, the percentage who got them fell from 64% (73/114) to 35% (35/101; aOR, 0.30; 95% CI, 0.17-0.52; P < .01). Only Hispanics had a statistically significant decline in Tdap vaccination (OR, 0.52, 95% CI, 0.34-0.80; P < .01, percentages not provided).

Another study presented at ACOG examined vaccination rates during the pandemic and found that Tdap vaccination rates dipped among pregnant women in a Philadelphia-area health care system.

Possible causes for the decline in routine vaccination include hesitancy linked to the COVID-19 vaccines and fewer office visits because of telemedicine, said Dr. Batan in an interview.

Dr. Permar blamed the role of vaccine misinformation during the pandemic and the mistrust caused by the exclusion of pregnant women from early vaccine trials. She added that “challenges in health care staffing and issues of health care provider burnout that worsened during the pandemic likely contributed to a fraying of the focus on preventive health maintenance simply due to bandwidth of health professionals.”

In a separate study presented at ACOG, researchers at the State University of New York, Syracuse, reported on a survey of 157 pregnant women of whom just 38.2% were vaccinated against COVID-19. Among the unvaccinated, who were more likely to have less education, 66% reported that lack of data about vaccination was their primary concern.

No funding or disclosures are reported by study authors. Dr. Permar reported consulting for Merck, Moderna, GlaxoSmithKline, Pfizer, Dynavax, and Hookipa on cytomegalovirus vaccine programs.

*This story was updated on 5/11/2022.

The percentage of low-income pregnant mothers who received influenza and Tdap vaccinations fell sharply during the COVID-19 pandemic, especially in Black and Hispanic patients, a new study finds.

The percentage of patients who received the influenza vaccines at two Medicaid clinics in Houston dropped from 78% before the pandemic to 61% during it (adjusted odds ratio, 0.38; 95% CI, 0.26-0.53; P < .01), researchers reported at the annual clinical and scientific meeting of the American College of Obstetricians and Gynecologists. The percentage receiving the Tdap vaccine dipped from 85% to 76% (aOR, 0.56; 95% CI, 0.40-0.79; P < .01).

New York–Presbyterian/Weill Cornell Medical Center pediatrician Sallie Permar, MD, PhD, who’s familiar with the study findings, called them “alarming” and said in an interview that they should be “a call to action for providers.”

“Continuing the status quo in our routine preventative health care and clinic operations means that we are losing ground in reduction and elimination of vaccine-preventable diseases,” Dr. Permar said in an interview.

According to corresponding author Bani Ratan, MD, an ob.gyn. with the Baylor College of Medicine, Houston, there’s been little if any previous research into routine, non-COVID vaccination in pregnant women during the pandemic.

For the study, researchers retrospectively analyzed the records of 939 pregnant women who entered prenatal care before 20 weeks (462 from May–November 2019, and 477 from May–November 2020) and delivered at full term.

Among ethnic groups, non-Hispanic Blacks saw the largest decline in influenza vaccines. Among them, the percentage who got them fell from 64% (73/114) to 35% (35/101; aOR, 0.30; 95% CI, 0.17-0.52; P < .01). Only Hispanics had a statistically significant decline in Tdap vaccination (OR, 0.52, 95% CI, 0.34-0.80; P < .01, percentages not provided).

Another study presented at ACOG examined vaccination rates during the pandemic and found that Tdap vaccination rates dipped among pregnant women in a Philadelphia-area health care system.

Possible causes for the decline in routine vaccination include hesitancy linked to the COVID-19 vaccines and fewer office visits because of telemedicine, said Dr. Batan in an interview.

Dr. Permar blamed the role of vaccine misinformation during the pandemic and the mistrust caused by the exclusion of pregnant women from early vaccine trials. She added that “challenges in health care staffing and issues of health care provider burnout that worsened during the pandemic likely contributed to a fraying of the focus on preventive health maintenance simply due to bandwidth of health professionals.”

In a separate study presented at ACOG, researchers at the State University of New York, Syracuse, reported on a survey of 157 pregnant women of whom just 38.2% were vaccinated against COVID-19. Among the unvaccinated, who were more likely to have less education, 66% reported that lack of data about vaccination was their primary concern.

No funding or disclosures are reported by study authors. Dr. Permar reported consulting for Merck, Moderna, GlaxoSmithKline, Pfizer, Dynavax, and Hookipa on cytomegalovirus vaccine programs.

*This story was updated on 5/11/2022.

The percentage of low-income pregnant mothers who received influenza and Tdap vaccinations fell sharply during the COVID-19 pandemic, especially in Black and Hispanic patients, a new study finds.

The percentage of patients who received the influenza vaccines at two Medicaid clinics in Houston dropped from 78% before the pandemic to 61% during it (adjusted odds ratio, 0.38; 95% CI, 0.26-0.53; P < .01), researchers reported at the annual clinical and scientific meeting of the American College of Obstetricians and Gynecologists. The percentage receiving the Tdap vaccine dipped from 85% to 76% (aOR, 0.56; 95% CI, 0.40-0.79; P < .01).

New York–Presbyterian/Weill Cornell Medical Center pediatrician Sallie Permar, MD, PhD, who’s familiar with the study findings, called them “alarming” and said in an interview that they should be “a call to action for providers.”

“Continuing the status quo in our routine preventative health care and clinic operations means that we are losing ground in reduction and elimination of vaccine-preventable diseases,” Dr. Permar said in an interview.

According to corresponding author Bani Ratan, MD, an ob.gyn. with the Baylor College of Medicine, Houston, there’s been little if any previous research into routine, non-COVID vaccination in pregnant women during the pandemic.

For the study, researchers retrospectively analyzed the records of 939 pregnant women who entered prenatal care before 20 weeks (462 from May–November 2019, and 477 from May–November 2020) and delivered at full term.

Among ethnic groups, non-Hispanic Blacks saw the largest decline in influenza vaccines. Among them, the percentage who got them fell from 64% (73/114) to 35% (35/101; aOR, 0.30; 95% CI, 0.17-0.52; P < .01). Only Hispanics had a statistically significant decline in Tdap vaccination (OR, 0.52, 95% CI, 0.34-0.80; P < .01, percentages not provided).

Another study presented at ACOG examined vaccination rates during the pandemic and found that Tdap vaccination rates dipped among pregnant women in a Philadelphia-area health care system.

Possible causes for the decline in routine vaccination include hesitancy linked to the COVID-19 vaccines and fewer office visits because of telemedicine, said Dr. Batan in an interview.

Dr. Permar blamed the role of vaccine misinformation during the pandemic and the mistrust caused by the exclusion of pregnant women from early vaccine trials. She added that “challenges in health care staffing and issues of health care provider burnout that worsened during the pandemic likely contributed to a fraying of the focus on preventive health maintenance simply due to bandwidth of health professionals.”

In a separate study presented at ACOG, researchers at the State University of New York, Syracuse, reported on a survey of 157 pregnant women of whom just 38.2% were vaccinated against COVID-19. Among the unvaccinated, who were more likely to have less education, 66% reported that lack of data about vaccination was their primary concern.

No funding or disclosures are reported by study authors. Dr. Permar reported consulting for Merck, Moderna, GlaxoSmithKline, Pfizer, Dynavax, and Hookipa on cytomegalovirus vaccine programs.

*This story was updated on 5/11/2022.

Coronavirus-related hospital admissions and deaths in the United States are projected to increase over the next four weeks, according to a national forecast used by the Centers for Disease Control and Prevention.

The national model also predicts that about 5,000 deaths will occur over the next two weeks, with Ohio, New Jersey, and New York projected to see the largest totals of daily deaths in upcoming weeks.

The numbers follow several weeks of steady increases in infections across the country. More than 67,000 new cases are being reported daily, according to the data tracker from The New York Times, marking a 59% increase in the past two weeks.

In the Northeast, infection rates have risen by nearly 65%. In the New York and New Jersey region, infection rates are up about 55% in the past two weeks.

Hospitalizations have already begun to climb as well, with about 19,000 COVID-19 patients hospitalized nationwide and 1,725 in intensive care, according to the latest data from the Department of Health and Human Services. In the last week, hospital admissions have jumped by 20%, and emergency department visits are up by 18%.

The CDC forecast shows that 42 states and territories will see increases in hospital admissions during the next two weeks. Florida, Minnesota, New York, and Wisconsin will see some of the largest increases.

On average, more than 2,200 COVID-19 patients are entering the hospital each day, which has increased about 20% in the last week, according to ABC News. This also marks the highest number of COVID-19 patients needing hospital care since mid-March.

Public health officials have cited several factors for the increase in cases, such as states lifting mask mandates and other safety restrictions, ABC News reported. Highly contagious Omicron subvariants, such as BA.2 and BA.2.12.1, continue to spread in the United States and escape immunity from previous infections.

The BA.2 subvariant accounts for 62% of new national cases, according to the latest CDC data. The BA.2.12.1 subvariant makes up about 36% of new cases across the United States but 62% in the New York area.

A version of this article first appeared on WebMD.com.

Coronavirus-related hospital admissions and deaths in the United States are projected to increase over the next four weeks, according to a national forecast used by the Centers for Disease Control and Prevention.

The national model also predicts that about 5,000 deaths will occur over the next two weeks, with Ohio, New Jersey, and New York projected to see the largest totals of daily deaths in upcoming weeks.

The numbers follow several weeks of steady increases in infections across the country. More than 67,000 new cases are being reported daily, according to the data tracker from The New York Times, marking a 59% increase in the past two weeks.

In the Northeast, infection rates have risen by nearly 65%. In the New York and New Jersey region, infection rates are up about 55% in the past two weeks.

Hospitalizations have already begun to climb as well, with about 19,000 COVID-19 patients hospitalized nationwide and 1,725 in intensive care, according to the latest data from the Department of Health and Human Services. In the last week, hospital admissions have jumped by 20%, and emergency department visits are up by 18%.

The CDC forecast shows that 42 states and territories will see increases in hospital admissions during the next two weeks. Florida, Minnesota, New York, and Wisconsin will see some of the largest increases.

On average, more than 2,200 COVID-19 patients are entering the hospital each day, which has increased about 20% in the last week, according to ABC News. This also marks the highest number of COVID-19 patients needing hospital care since mid-March.

Public health officials have cited several factors for the increase in cases, such as states lifting mask mandates and other safety restrictions, ABC News reported. Highly contagious Omicron subvariants, such as BA.2 and BA.2.12.1, continue to spread in the United States and escape immunity from previous infections.

The BA.2 subvariant accounts for 62% of new national cases, according to the latest CDC data. The BA.2.12.1 subvariant makes up about 36% of new cases across the United States but 62% in the New York area.

A version of this article first appeared on WebMD.com.

Coronavirus-related hospital admissions and deaths in the United States are projected to increase over the next four weeks, according to a national forecast used by the Centers for Disease Control and Prevention.

The national model also predicts that about 5,000 deaths will occur over the next two weeks, with Ohio, New Jersey, and New York projected to see the largest totals of daily deaths in upcoming weeks.

The numbers follow several weeks of steady increases in infections across the country. More than 67,000 new cases are being reported daily, according to the data tracker from The New York Times, marking a 59% increase in the past two weeks.

In the Northeast, infection rates have risen by nearly 65%. In the New York and New Jersey region, infection rates are up about 55% in the past two weeks.

Hospitalizations have already begun to climb as well, with about 19,000 COVID-19 patients hospitalized nationwide and 1,725 in intensive care, according to the latest data from the Department of Health and Human Services. In the last week, hospital admissions have jumped by 20%, and emergency department visits are up by 18%.

The CDC forecast shows that 42 states and territories will see increases in hospital admissions during the next two weeks. Florida, Minnesota, New York, and Wisconsin will see some of the largest increases.

On average, more than 2,200 COVID-19 patients are entering the hospital each day, which has increased about 20% in the last week, according to ABC News. This also marks the highest number of COVID-19 patients needing hospital care since mid-March.

Public health officials have cited several factors for the increase in cases, such as states lifting mask mandates and other safety restrictions, ABC News reported. Highly contagious Omicron subvariants, such as BA.2 and BA.2.12.1, continue to spread in the United States and escape immunity from previous infections.

The BA.2 subvariant accounts for 62% of new national cases, according to the latest CDC data. The BA.2.12.1 subvariant makes up about 36% of new cases across the United States but 62% in the New York area.

A version of this article first appeared on WebMD.com.

An investigational, novel oral antibiotic with greater selectivity than vancomycin, metronidazole, and even fidaxomicin may offer improved protection of healthy gut bacteria during the treatment of Clostridium difficile infection (CDI), according to ongoing research.

“CDI treatment has historically been dominated by metronidazole and vancomycin,” said Katherine Johnson, DO, from the Western Infectious Disease Consultants, P.C., Denver. However, these broad-spectrum drugs negatively affect healthy bacteria in the gut and increase the risk of CDI recurrence.

This is also a problem for drugs in the CDI antibiotic pipeline: Many candidate drugs have failed because of their broad-spectrum activity, she added during a session at the Peggy Lillis Foundation 2022 National C. diff. Advocacy Summit.

“An ideal CDI therapy would be a very narrow-spectrum antibiotic that has a minimal effect on normal gut bacteria,” she said.

Dr. Johnson is currently working on a phase 2 clinical trial that is evaluating the novel antibiotic, dubbed CRS3123, for the treatment of primary CDI and first-recurrence CDI. The investigational agent targets and inhibits a form of the methionyl tRNA synthetase enzyme, which is strictly required for protein biosynthesis in C. diff. and is therefore an ideal target for treatment of primary and recurrent CDI.

In her session, Dr. Johnson reported that CRS3123 inhibits the damaging toxins produced by C. diff., potentially resulting in more rapid symptom resolution. Additionally, owing to its novel mode of action, no strains are currently resistant to CRS3123.

She presented findings from an animal study that showed that CRS3123 was superior to vancomycin in terms of prolonging survival. She also presented findings from phase 1 clinical trials that showed that most adverse events (AEs) associated with CRS3123 were mild. No serious AEs were reported.
 

A ‘huge infectious burden’

If successful in further research, CRS3123 could offer significant value to patients with C. diff., especially those with recurrent infection, given the sometimes extreme clinical, quality-of-life, and economic burdens associated with CDI.

“CDI is a huge infectious burden to the U.S. health care system and globally has been listed by the Centers for Disease Control and Prevention as an urgent threat,” Byron Vaughn, MD, from the University of Minnesota, told this news organization.

“Despite a number of antibiotic stewardship and infection control and prevention efforts, we haven’t seen much of a change in the incidence of CDI,” he said. He said that the risk of recurrence can be as high as 30%.

While oral vancomycin is effective for treating C. diff., Dr. Vaughn noted that the antibiotic lacks selectivity and destroys healthy gut bacteria, resulting in substantial dysbiosis. “Dysbiosis is really the key to getting recurrent C. diff.,” he explained, “because if you have healthy gut bacteria, you will inherently resist CDI.”

Dr. Vaughn stated that his center is in the startup phase for being a site for a clinical trial of CRS3123. The hope is that CRS3123, because its spectrum is narrower than that of fidaxomicin and vancomycin, doesn’t induce intestinal dysbiosis. “It really just treats the C. diff. and leaves every other bug alone so that your gut bacteria can recover while the C. diff. is being treated,” he said. “And then when you stop CRS3123, you have healthy gut bacteria already present to prevent recurrence.”

If this is confirmed in large-scale trials, there could be a “dramatic decrease” in the rates of recurrent C. diff., said Dr. Vaughn.

Aside from the potential clinical impact, the economic implications of a novel selective antibiotic that preserves healthy gut bacteria could be significant, he added. “Depending on exactly what population you’re looking at, probably about a third of the cost of C. diff. is actually attributable to recurrence. That’s a huge economic burden that could be improved.”

Dr. Johnson is an employee of Crestone, which is developing CRS3123. Dr. Vaughn reports no relevant financial relationships.

A version of this article first appeared on Medscape.com.

An investigational, novel oral antibiotic with greater selectivity than vancomycin, metronidazole, and even fidaxomicin may offer improved protection of healthy gut bacteria during the treatment of Clostridium difficile infection (CDI), according to ongoing research.

“CDI treatment has historically been dominated by metronidazole and vancomycin,” said Katherine Johnson, DO, from the Western Infectious Disease Consultants, P.C., Denver. However, these broad-spectrum drugs negatively affect healthy bacteria in the gut and increase the risk of CDI recurrence.

This is also a problem for drugs in the CDI antibiotic pipeline: Many candidate drugs have failed because of their broad-spectrum activity, she added during a session at the Peggy Lillis Foundation 2022 National C. diff. Advocacy Summit.

“An ideal CDI therapy would be a very narrow-spectrum antibiotic that has a minimal effect on normal gut bacteria,” she said.

Dr. Johnson is currently working on a phase 2 clinical trial that is evaluating the novel antibiotic, dubbed CRS3123, for the treatment of primary CDI and first-recurrence CDI. The investigational agent targets and inhibits a form of the methionyl tRNA synthetase enzyme, which is strictly required for protein biosynthesis in C. diff. and is therefore an ideal target for treatment of primary and recurrent CDI.

In her session, Dr. Johnson reported that CRS3123 inhibits the damaging toxins produced by C. diff., potentially resulting in more rapid symptom resolution. Additionally, owing to its novel mode of action, no strains are currently resistant to CRS3123.

She presented findings from an animal study that showed that CRS3123 was superior to vancomycin in terms of prolonging survival. She also presented findings from phase 1 clinical trials that showed that most adverse events (AEs) associated with CRS3123 were mild. No serious AEs were reported.
 

A ‘huge infectious burden’

If successful in further research, CRS3123 could offer significant value to patients with C. diff., especially those with recurrent infection, given the sometimes extreme clinical, quality-of-life, and economic burdens associated with CDI.

“CDI is a huge infectious burden to the U.S. health care system and globally has been listed by the Centers for Disease Control and Prevention as an urgent threat,” Byron Vaughn, MD, from the University of Minnesota, told this news organization.

“Despite a number of antibiotic stewardship and infection control and prevention efforts, we haven’t seen much of a change in the incidence of CDI,” he said. He said that the risk of recurrence can be as high as 30%.

While oral vancomycin is effective for treating C. diff., Dr. Vaughn noted that the antibiotic lacks selectivity and destroys healthy gut bacteria, resulting in substantial dysbiosis. “Dysbiosis is really the key to getting recurrent C. diff.,” he explained, “because if you have healthy gut bacteria, you will inherently resist CDI.”

Dr. Vaughn stated that his center is in the startup phase for being a site for a clinical trial of CRS3123. The hope is that CRS3123, because its spectrum is narrower than that of fidaxomicin and vancomycin, doesn’t induce intestinal dysbiosis. “It really just treats the C. diff. and leaves every other bug alone so that your gut bacteria can recover while the C. diff. is being treated,” he said. “And then when you stop CRS3123, you have healthy gut bacteria already present to prevent recurrence.”

If this is confirmed in large-scale trials, there could be a “dramatic decrease” in the rates of recurrent C. diff., said Dr. Vaughn.

Aside from the potential clinical impact, the economic implications of a novel selective antibiotic that preserves healthy gut bacteria could be significant, he added. “Depending on exactly what population you’re looking at, probably about a third of the cost of C. diff. is actually attributable to recurrence. That’s a huge economic burden that could be improved.”

Dr. Johnson is an employee of Crestone, which is developing CRS3123. Dr. Vaughn reports no relevant financial relationships.

A version of this article first appeared on Medscape.com.

An investigational, novel oral antibiotic with greater selectivity than vancomycin, metronidazole, and even fidaxomicin may offer improved protection of healthy gut bacteria during the treatment of Clostridium difficile infection (CDI), according to ongoing research.

“CDI treatment has historically been dominated by metronidazole and vancomycin,” said Katherine Johnson, DO, from the Western Infectious Disease Consultants, P.C., Denver. However, these broad-spectrum drugs negatively affect healthy bacteria in the gut and increase the risk of CDI recurrence.

This is also a problem for drugs in the CDI antibiotic pipeline: Many candidate drugs have failed because of their broad-spectrum activity, she added during a session at the Peggy Lillis Foundation 2022 National C. diff. Advocacy Summit.

“An ideal CDI therapy would be a very narrow-spectrum antibiotic that has a minimal effect on normal gut bacteria,” she said.

Dr. Johnson is currently working on a phase 2 clinical trial that is evaluating the novel antibiotic, dubbed CRS3123, for the treatment of primary CDI and first-recurrence CDI. The investigational agent targets and inhibits a form of the methionyl tRNA synthetase enzyme, which is strictly required for protein biosynthesis in C. diff. and is therefore an ideal target for treatment of primary and recurrent CDI.

In her session, Dr. Johnson reported that CRS3123 inhibits the damaging toxins produced by C. diff., potentially resulting in more rapid symptom resolution. Additionally, owing to its novel mode of action, no strains are currently resistant to CRS3123.

She presented findings from an animal study that showed that CRS3123 was superior to vancomycin in terms of prolonging survival. She also presented findings from phase 1 clinical trials that showed that most adverse events (AEs) associated with CRS3123 were mild. No serious AEs were reported.
 

A ‘huge infectious burden’

If successful in further research, CRS3123 could offer significant value to patients with C. diff., especially those with recurrent infection, given the sometimes extreme clinical, quality-of-life, and economic burdens associated with CDI.

“CDI is a huge infectious burden to the U.S. health care system and globally has been listed by the Centers for Disease Control and Prevention as an urgent threat,” Byron Vaughn, MD, from the University of Minnesota, told this news organization.

“Despite a number of antibiotic stewardship and infection control and prevention efforts, we haven’t seen much of a change in the incidence of CDI,” he said. He said that the risk of recurrence can be as high as 30%.

While oral vancomycin is effective for treating C. diff., Dr. Vaughn noted that the antibiotic lacks selectivity and destroys healthy gut bacteria, resulting in substantial dysbiosis. “Dysbiosis is really the key to getting recurrent C. diff.,” he explained, “because if you have healthy gut bacteria, you will inherently resist CDI.”

Dr. Vaughn stated that his center is in the startup phase for being a site for a clinical trial of CRS3123. The hope is that CRS3123, because its spectrum is narrower than that of fidaxomicin and vancomycin, doesn’t induce intestinal dysbiosis. “It really just treats the C. diff. and leaves every other bug alone so that your gut bacteria can recover while the C. diff. is being treated,” he said. “And then when you stop CRS3123, you have healthy gut bacteria already present to prevent recurrence.”

If this is confirmed in large-scale trials, there could be a “dramatic decrease” in the rates of recurrent C. diff., said Dr. Vaughn.

Aside from the potential clinical impact, the economic implications of a novel selective antibiotic that preserves healthy gut bacteria could be significant, he added. “Depending on exactly what population you’re looking at, probably about a third of the cost of C. diff. is actually attributable to recurrence. That’s a huge economic burden that could be improved.”

Dr. Johnson is an employee of Crestone, which is developing CRS3123. Dr. Vaughn reports no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Clostridioides difficile infection is often confirmed through toxin testing, yet toxin tests alone may not be sufficient for diagnosing and guiding treatment decisions for patients with CDI.

“The presence of a toxigenic strain does not always equal disease,” said David Lyerly, PhD, during a session on C. difficile toxin testing at the Peggy Lillis Foundation 2022 National C. diff Advocacy Summit.

Dr. Lyerly, the chief science officer at Techlab, explained that exotoxins A and B are produced by specific strains of C. difficile and are involved in infections, but some patients who test positive for these toxins by polymerase chain reaction or other tests do not have CDI or they are not appropriate candidates for CDI treatment.

Several studies conducted during the past decade, however, support the importance of toxin detection. Some research has suggested that toxin-positive patients tend to have more clinically severe disease than those who test negative, he noted.

Although its use is limited when it is used alone, toxin testing is needed to confirm a CDI diagnosis and to ensure antibiotic stewardship, Dr. Lyerly said.

He suggested that, in addition to toxin testing, there is a need for molecular measures and other improved diagnostics to identify candidates most likely to benefit from CDI treatment.

“Because we generally detect toxin genes instead of toxin proteins, you can identify persons colonized with toxigenic C. difficile who do not actually have CDI,” Kevin W. Garey, PharmD, from the University of Houston, said in an interview.

Dr. Garey added that a person could likewise have low levels of toxins that aren’t detected by toxin tests but could still have CDI.

“Given this, better diagnostics that incorporate active toxin production and your body’s response to those toxins are needed,” he said, especially since C. difficile toxins are responsible for disease sequelae, including gastroenteritis, colonic perforation, sepsis, and death.
 

Toxin testing a ‘controversial area’

“C. difficile toxin testing has been a controversial area for almost a decade or more,” Shruti K. Gohil, MD, from University of California, Irvine, Health Epidemiology and Infection Prevention, said in an interview.

Dr. Gohil noted that toxin testing is a better test for clinical C. difficile colitis but by itself can miss C. difficile. “So, we are in this conundrum nationally,” she said.

“Many facilities will use a double- or triple-test strategy to make sure that you have a true C. difficile case mandating the use of antibiotics,” she explained. “The reason we test specifically with the enzyme immunoassay or toxin test is to know whether or not you have real C. difficile that’s actively producing the toxin for colitis.”

A patient with C. difficile who has been treated and is in recovery may still test positive on a C. difficile toxin test, added Dr. Gohil. “It would be great if we had a test that could really judge an active, clinical C. difficile infection. This [test] would help in identifying the right patients who need treatment and would also be able to tell if a patient has been cleared of C. difficile.”

Dr. Lyerly is an employee of Techlab. Dr. Garey and Dr. Gohil reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Clostridioides difficile infection is often confirmed through toxin testing, yet toxin tests alone may not be sufficient for diagnosing and guiding treatment decisions for patients with CDI.

“The presence of a toxigenic strain does not always equal disease,” said David Lyerly, PhD, during a session on C. difficile toxin testing at the Peggy Lillis Foundation 2022 National C. diff Advocacy Summit.

Dr. Lyerly, the chief science officer at Techlab, explained that exotoxins A and B are produced by specific strains of C. difficile and are involved in infections, but some patients who test positive for these toxins by polymerase chain reaction or other tests do not have CDI or they are not appropriate candidates for CDI treatment.

Several studies conducted during the past decade, however, support the importance of toxin detection. Some research has suggested that toxin-positive patients tend to have more clinically severe disease than those who test negative, he noted.

Although its use is limited when it is used alone, toxin testing is needed to confirm a CDI diagnosis and to ensure antibiotic stewardship, Dr. Lyerly said.

He suggested that, in addition to toxin testing, there is a need for molecular measures and other improved diagnostics to identify candidates most likely to benefit from CDI treatment.

“Because we generally detect toxin genes instead of toxin proteins, you can identify persons colonized with toxigenic C. difficile who do not actually have CDI,” Kevin W. Garey, PharmD, from the University of Houston, said in an interview.

Dr. Garey added that a person could likewise have low levels of toxins that aren’t detected by toxin tests but could still have CDI.

“Given this, better diagnostics that incorporate active toxin production and your body’s response to those toxins are needed,” he said, especially since C. difficile toxins are responsible for disease sequelae, including gastroenteritis, colonic perforation, sepsis, and death.
 

Toxin testing a ‘controversial area’

“C. difficile toxin testing has been a controversial area for almost a decade or more,” Shruti K. Gohil, MD, from University of California, Irvine, Health Epidemiology and Infection Prevention, said in an interview.

Dr. Gohil noted that toxin testing is a better test for clinical C. difficile colitis but by itself can miss C. difficile. “So, we are in this conundrum nationally,” she said.

“Many facilities will use a double- or triple-test strategy to make sure that you have a true C. difficile case mandating the use of antibiotics,” she explained. “The reason we test specifically with the enzyme immunoassay or toxin test is to know whether or not you have real C. difficile that’s actively producing the toxin for colitis.”

A patient with C. difficile who has been treated and is in recovery may still test positive on a C. difficile toxin test, added Dr. Gohil. “It would be great if we had a test that could really judge an active, clinical C. difficile infection. This [test] would help in identifying the right patients who need treatment and would also be able to tell if a patient has been cleared of C. difficile.”

Dr. Lyerly is an employee of Techlab. Dr. Garey and Dr. Gohil reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Clostridioides difficile infection is often confirmed through toxin testing, yet toxin tests alone may not be sufficient for diagnosing and guiding treatment decisions for patients with CDI.

“The presence of a toxigenic strain does not always equal disease,” said David Lyerly, PhD, during a session on C. difficile toxin testing at the Peggy Lillis Foundation 2022 National C. diff Advocacy Summit.

Dr. Lyerly, the chief science officer at Techlab, explained that exotoxins A and B are produced by specific strains of C. difficile and are involved in infections, but some patients who test positive for these toxins by polymerase chain reaction or other tests do not have CDI or they are not appropriate candidates for CDI treatment.

Several studies conducted during the past decade, however, support the importance of toxin detection. Some research has suggested that toxin-positive patients tend to have more clinically severe disease than those who test negative, he noted.

Although its use is limited when it is used alone, toxin testing is needed to confirm a CDI diagnosis and to ensure antibiotic stewardship, Dr. Lyerly said.

He suggested that, in addition to toxin testing, there is a need for molecular measures and other improved diagnostics to identify candidates most likely to benefit from CDI treatment.

“Because we generally detect toxin genes instead of toxin proteins, you can identify persons colonized with toxigenic C. difficile who do not actually have CDI,” Kevin W. Garey, PharmD, from the University of Houston, said in an interview.

Dr. Garey added that a person could likewise have low levels of toxins that aren’t detected by toxin tests but could still have CDI.

“Given this, better diagnostics that incorporate active toxin production and your body’s response to those toxins are needed,” he said, especially since C. difficile toxins are responsible for disease sequelae, including gastroenteritis, colonic perforation, sepsis, and death.
 

Toxin testing a ‘controversial area’

“C. difficile toxin testing has been a controversial area for almost a decade or more,” Shruti K. Gohil, MD, from University of California, Irvine, Health Epidemiology and Infection Prevention, said in an interview.

Dr. Gohil noted that toxin testing is a better test for clinical C. difficile colitis but by itself can miss C. difficile. “So, we are in this conundrum nationally,” she said.

“Many facilities will use a double- or triple-test strategy to make sure that you have a true C. difficile case mandating the use of antibiotics,” she explained. “The reason we test specifically with the enzyme immunoassay or toxin test is to know whether or not you have real C. difficile that’s actively producing the toxin for colitis.”

A patient with C. difficile who has been treated and is in recovery may still test positive on a C. difficile toxin test, added Dr. Gohil. “It would be great if we had a test that could really judge an active, clinical C. difficile infection. This [test] would help in identifying the right patients who need treatment and would also be able to tell if a patient has been cleared of C. difficile.”

Dr. Lyerly is an employee of Techlab. Dr. Garey and Dr. Gohil reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

This spring, global health advisories have been issued regarding an alarming – and as-yet unexplained – uptick of hepatitis in children. Currently, over 200 cases have been reported worldwide, a relatively small amount that nonetheless belies a considerable toll, including several deaths and the need for liver transplantation in a number of patients. The long-term implications are not yet known. Global health officials are working hard to determine a cause, with many focusing on the underlying cases of adenovirus that several patients have presented with.

To understand more, this news organization reached out to frequent contributor William F. Balistreri, MD, a specialist in pediatric gastroenterology and hepatology at Cincinnati Children’s Hospital Medical Center, where to date they have treated at least six cases of hepatitis in otherwise healthy young children, with one requiring a liver transplant. Dr. Balistreri discussed how the outbreak has developed to date, his advice to hepatologists and pediatricians, and where we stand now in this fast-evolving crisis.
 

Tracing the outbreak in the United States

How has this outbreak played out thus far in the United States, and what have we learned from that?

Sporadic reports of cases in multiple states are appearing. On April 21, 2022, a health alert was issued by the Centers for Disease Control and Prevention, recommending testing for adenovirus in children with acute hepatitis of an unknown etiology.

Baker and colleagues recently described five children with severe hepatitis and adenovirus viremia who were admitted to a children’s hospital in Birmingham, Ala., between October and November 2021. In collaboration with local and state officials, the CDC reviewed clinical records in order to identify patients with hepatitis and concomitant adenovirus infection, confirmed by polymerase chain reaction (PCR).

By February 2022, a total of nine children were identified. There was no epidemiologic linkage among these nine patients; all were well and immunocompetent. The prodromal features were somewhat similar: upper respiratory infection, vomiting, diarrhea, and jaundice. All children had markedly elevated aminotransferase levels and variably elevated total bilirubin levels. Extensive workup for other causes of acute liver injury (for example, other viruses, toxins/drugs, metabolic and autoimmune diseases) was unrevealing.

Specifically, none had documented SARS-CoV-2 infection. However, in all nine children, adenovirus was detected in whole blood samples. In the six children who underwent liver biopsy, there was nonspecific hepatitis, without inclusions or immunohistochemical detection of viral agents, including adenovirus. In three patients, the liver injury progressed, and despite the administration of antiviral agents, two underwent liver transplantation.

Baker and colleagues also suggested that measurement of adenovirus titers in whole blood (rather than plasma) may be more sensitive.

The CDC has recommended monitoring and surveillance in order to more fully understand the nature of the illness.
 

European and global cases

What has been the experience with this in Europe and elsewhere globally?

In mid-to-late 2021, several cases of acute hepatitis of unknown nature in children were identified in Europe. Public health officials in the United Kingdom investigated the high number of cases seen in children from England, Scotland, and Wales. They noted approximately 60 cases in England, mostly in children aged 2-5 years.

Marsh and colleagues reported a cluster of cases of severe hepatitis of unknown origin in Scotland affecting children aged 3-5 years. In Scotland, admitted cases were routinely tested for SARS-CoV-2. Of the 13 cases, five had a recent positive test. They discussed the possibility of increased severity of disease following infection with Omicron BA.2 (the dominant SARS-CoV-2 virus circulating in Scotland at that time) or infection by an uncharacterized SARS-CoV-2 variant. None of the children had been vaccinated for SARS-CoV-2.

On April 15, 2022, the World Health Organization Disease Outbreak News published a report of acute hepatitis of unknown etiology occurring in Great Britain and Northern Ireland. By April 21, 2022, 169 cases of acute hepatitis of unknown origin in children younger than 16 years had been reported from 11 countries in the WHO European region and 1 country in the WHO region of the Americas. Approximately 10% required a liver transplantation and at least one death was reported.

What has been established about the possible connection to the SARS-CoV-2 virus, particularly as it relates to coinfection with adenovirus?

In that WHO report of 169 cases, adenovirus was detected in 74 and SARS-CoV-2 in 20. Of note, 19 cases had a SARS-CoV-2 and adenovirus coinfection.

The report’s authors emphasized that, “while adenovirus is a possible hypothesis, investigations are ongoing for the causative agent.” The authors questioned whether this represents a continuing increase in cases of hepatitis or reflects an increased awareness.

The stated priority of the WHO is to determine the cause and to further refine control and prevention actions.

Given the worldwide nature of this outbreak, have connections between any of the cases been made yet?

Not to my knowledge.
 

What clinicians need to know

What makes this outbreak of hepatitis cases particularly concerning to the health care community, in comparison to other childhood diseases that occur globally? Is it because the cause is unknown or is it for other reasons?

It may be a collective heightened concern following the emergence of COVID.

Whether it represents a new form of acute hepatitis, a continuing increase in cases of hepatitis, or an increased awareness because of the well-publicized alerts remains to be determined. We certainly saw “viral-induced hepatitis” in the past.

Young patients may first be brought to pediatricians. What, if anything, should pediatricians be on the lookout for? Do they need a heightened index of suspicion or are the cases too rare at this point?

An awareness of the “outbreak” may allow the clinician to extend the typical workup of a child presenting with an undefined, presumably viral illness.

In the cases reported, the prodromal and/or presenting symptoms were respiratory and gastrointestinal in nature. They include nausea, vomiting, diarrhea, and abdominal pain.

Specifically, if jaundice and/or scleral icterus is noted, then hepatitis should be suspected.

Should pediatricians consider early referral to a pediatric gastroenterologist or hepatologist?

Yes, because there is the potential for finding a treatable cause (for example, autoimmune hepatitis or a specific metabolic disease) in a patient presenting in this fashion.

In addition, the potential for progression to acute liver failure (with coagulopathy and encephalopathy), albeit rare, exists.

What do hepatologists need to be doing when presented with suspected cases?

The typical clinical picture holds and the workup is standard. The one new key, given the recent data, is to test for adenovirus, using whole blood versus plasma, as the former may be more sensitive.

In addition, it is prudent to check for SARS-CoV-2 by PCR.

What are the major questions that remain and that you’d like to see elucidated going forward?

There are many. Is this a new disease? A new variant of adenovirus? A synergy or susceptibility related to SARS-CoV-2? Is it related to a variant of SARS-CoV-2? Is it triggering an adverse immune response? Are there other epigenetic factors involved? And finally, is this an increase, or is it related to a collective heightened concern following the pandemic?

Dr. Balistreri is the Dorothy M.M. Kersten Professor of Pediatrics, director emeritus of the Pediatric Liver Care Center, medical director emeritus of liver transplantation, and professor at the University of Cincinnati; he is also with the department of pediatrics at Cincinnati Children’s Hospital Medical Center.

A version of this article first appeared on Medscape.com.

This spring, global health advisories have been issued regarding an alarming – and as-yet unexplained – uptick of hepatitis in children. Currently, over 200 cases have been reported worldwide, a relatively small amount that nonetheless belies a considerable toll, including several deaths and the need for liver transplantation in a number of patients. The long-term implications are not yet known. Global health officials are working hard to determine a cause, with many focusing on the underlying cases of adenovirus that several patients have presented with.

To understand more, this news organization reached out to frequent contributor William F. Balistreri, MD, a specialist in pediatric gastroenterology and hepatology at Cincinnati Children’s Hospital Medical Center, where to date they have treated at least six cases of hepatitis in otherwise healthy young children, with one requiring a liver transplant. Dr. Balistreri discussed how the outbreak has developed to date, his advice to hepatologists and pediatricians, and where we stand now in this fast-evolving crisis.
 

Tracing the outbreak in the United States

How has this outbreak played out thus far in the United States, and what have we learned from that?

Sporadic reports of cases in multiple states are appearing. On April 21, 2022, a health alert was issued by the Centers for Disease Control and Prevention, recommending testing for adenovirus in children with acute hepatitis of an unknown etiology.

Baker and colleagues recently described five children with severe hepatitis and adenovirus viremia who were admitted to a children’s hospital in Birmingham, Ala., between October and November 2021. In collaboration with local and state officials, the CDC reviewed clinical records in order to identify patients with hepatitis and concomitant adenovirus infection, confirmed by polymerase chain reaction (PCR).

By February 2022, a total of nine children were identified. There was no epidemiologic linkage among these nine patients; all were well and immunocompetent. The prodromal features were somewhat similar: upper respiratory infection, vomiting, diarrhea, and jaundice. All children had markedly elevated aminotransferase levels and variably elevated total bilirubin levels. Extensive workup for other causes of acute liver injury (for example, other viruses, toxins/drugs, metabolic and autoimmune diseases) was unrevealing.

Specifically, none had documented SARS-CoV-2 infection. However, in all nine children, adenovirus was detected in whole blood samples. In the six children who underwent liver biopsy, there was nonspecific hepatitis, without inclusions or immunohistochemical detection of viral agents, including adenovirus. In three patients, the liver injury progressed, and despite the administration of antiviral agents, two underwent liver transplantation.

Baker and colleagues also suggested that measurement of adenovirus titers in whole blood (rather than plasma) may be more sensitive.

The CDC has recommended monitoring and surveillance in order to more fully understand the nature of the illness.
 

European and global cases

What has been the experience with this in Europe and elsewhere globally?

In mid-to-late 2021, several cases of acute hepatitis of unknown nature in children were identified in Europe. Public health officials in the United Kingdom investigated the high number of cases seen in children from England, Scotland, and Wales. They noted approximately 60 cases in England, mostly in children aged 2-5 years.

Marsh and colleagues reported a cluster of cases of severe hepatitis of unknown origin in Scotland affecting children aged 3-5 years. In Scotland, admitted cases were routinely tested for SARS-CoV-2. Of the 13 cases, five had a recent positive test. They discussed the possibility of increased severity of disease following infection with Omicron BA.2 (the dominant SARS-CoV-2 virus circulating in Scotland at that time) or infection by an uncharacterized SARS-CoV-2 variant. None of the children had been vaccinated for SARS-CoV-2.

On April 15, 2022, the World Health Organization Disease Outbreak News published a report of acute hepatitis of unknown etiology occurring in Great Britain and Northern Ireland. By April 21, 2022, 169 cases of acute hepatitis of unknown origin in children younger than 16 years had been reported from 11 countries in the WHO European region and 1 country in the WHO region of the Americas. Approximately 10% required a liver transplantation and at least one death was reported.

What has been established about the possible connection to the SARS-CoV-2 virus, particularly as it relates to coinfection with adenovirus?

In that WHO report of 169 cases, adenovirus was detected in 74 and SARS-CoV-2 in 20. Of note, 19 cases had a SARS-CoV-2 and adenovirus coinfection.

The report’s authors emphasized that, “while adenovirus is a possible hypothesis, investigations are ongoing for the causative agent.” The authors questioned whether this represents a continuing increase in cases of hepatitis or reflects an increased awareness.

The stated priority of the WHO is to determine the cause and to further refine control and prevention actions.

Given the worldwide nature of this outbreak, have connections between any of the cases been made yet?

Not to my knowledge.
 

What clinicians need to know

What makes this outbreak of hepatitis cases particularly concerning to the health care community, in comparison to other childhood diseases that occur globally? Is it because the cause is unknown or is it for other reasons?

It may be a collective heightened concern following the emergence of COVID.

Whether it represents a new form of acute hepatitis, a continuing increase in cases of hepatitis, or an increased awareness because of the well-publicized alerts remains to be determined. We certainly saw “viral-induced hepatitis” in the past.

Young patients may first be brought to pediatricians. What, if anything, should pediatricians be on the lookout for? Do they need a heightened index of suspicion or are the cases too rare at this point?

An awareness of the “outbreak” may allow the clinician to extend the typical workup of a child presenting with an undefined, presumably viral illness.

In the cases reported, the prodromal and/or presenting symptoms were respiratory and gastrointestinal in nature. They include nausea, vomiting, diarrhea, and abdominal pain.

Specifically, if jaundice and/or scleral icterus is noted, then hepatitis should be suspected.

Should pediatricians consider early referral to a pediatric gastroenterologist or hepatologist?

Yes, because there is the potential for finding a treatable cause (for example, autoimmune hepatitis or a specific metabolic disease) in a patient presenting in this fashion.

In addition, the potential for progression to acute liver failure (with coagulopathy and encephalopathy), albeit rare, exists.

What do hepatologists need to be doing when presented with suspected cases?

The typical clinical picture holds and the workup is standard. The one new key, given the recent data, is to test for adenovirus, using whole blood versus plasma, as the former may be more sensitive.

In addition, it is prudent to check for SARS-CoV-2 by PCR.

What are the major questions that remain and that you’d like to see elucidated going forward?

There are many. Is this a new disease? A new variant of adenovirus? A synergy or susceptibility related to SARS-CoV-2? Is it related to a variant of SARS-CoV-2? Is it triggering an adverse immune response? Are there other epigenetic factors involved? And finally, is this an increase, or is it related to a collective heightened concern following the pandemic?

Dr. Balistreri is the Dorothy M.M. Kersten Professor of Pediatrics, director emeritus of the Pediatric Liver Care Center, medical director emeritus of liver transplantation, and professor at the University of Cincinnati; he is also with the department of pediatrics at Cincinnati Children’s Hospital Medical Center.

A version of this article first appeared on Medscape.com.

This spring, global health advisories have been issued regarding an alarming – and as-yet unexplained – uptick of hepatitis in children. Currently, over 200 cases have been reported worldwide, a relatively small amount that nonetheless belies a considerable toll, including several deaths and the need for liver transplantation in a number of patients. The long-term implications are not yet known. Global health officials are working hard to determine a cause, with many focusing on the underlying cases of adenovirus that several patients have presented with.

To understand more, this news organization reached out to frequent contributor William F. Balistreri, MD, a specialist in pediatric gastroenterology and hepatology at Cincinnati Children’s Hospital Medical Center, where to date they have treated at least six cases of hepatitis in otherwise healthy young children, with one requiring a liver transplant. Dr. Balistreri discussed how the outbreak has developed to date, his advice to hepatologists and pediatricians, and where we stand now in this fast-evolving crisis.
 

Tracing the outbreak in the United States

How has this outbreak played out thus far in the United States, and what have we learned from that?

Sporadic reports of cases in multiple states are appearing. On April 21, 2022, a health alert was issued by the Centers for Disease Control and Prevention, recommending testing for adenovirus in children with acute hepatitis of an unknown etiology.

Baker and colleagues recently described five children with severe hepatitis and adenovirus viremia who were admitted to a children’s hospital in Birmingham, Ala., between October and November 2021. In collaboration with local and state officials, the CDC reviewed clinical records in order to identify patients with hepatitis and concomitant adenovirus infection, confirmed by polymerase chain reaction (PCR).

By February 2022, a total of nine children were identified. There was no epidemiologic linkage among these nine patients; all were well and immunocompetent. The prodromal features were somewhat similar: upper respiratory infection, vomiting, diarrhea, and jaundice. All children had markedly elevated aminotransferase levels and variably elevated total bilirubin levels. Extensive workup for other causes of acute liver injury (for example, other viruses, toxins/drugs, metabolic and autoimmune diseases) was unrevealing.

Specifically, none had documented SARS-CoV-2 infection. However, in all nine children, adenovirus was detected in whole blood samples. In the six children who underwent liver biopsy, there was nonspecific hepatitis, without inclusions or immunohistochemical detection of viral agents, including adenovirus. In three patients, the liver injury progressed, and despite the administration of antiviral agents, two underwent liver transplantation.

Baker and colleagues also suggested that measurement of adenovirus titers in whole blood (rather than plasma) may be more sensitive.

The CDC has recommended monitoring and surveillance in order to more fully understand the nature of the illness.
 

European and global cases

What has been the experience with this in Europe and elsewhere globally?

In mid-to-late 2021, several cases of acute hepatitis of unknown nature in children were identified in Europe. Public health officials in the United Kingdom investigated the high number of cases seen in children from England, Scotland, and Wales. They noted approximately 60 cases in England, mostly in children aged 2-5 years.

Marsh and colleagues reported a cluster of cases of severe hepatitis of unknown origin in Scotland affecting children aged 3-5 years. In Scotland, admitted cases were routinely tested for SARS-CoV-2. Of the 13 cases, five had a recent positive test. They discussed the possibility of increased severity of disease following infection with Omicron BA.2 (the dominant SARS-CoV-2 virus circulating in Scotland at that time) or infection by an uncharacterized SARS-CoV-2 variant. None of the children had been vaccinated for SARS-CoV-2.

On April 15, 2022, the World Health Organization Disease Outbreak News published a report of acute hepatitis of unknown etiology occurring in Great Britain and Northern Ireland. By April 21, 2022, 169 cases of acute hepatitis of unknown origin in children younger than 16 years had been reported from 11 countries in the WHO European region and 1 country in the WHO region of the Americas. Approximately 10% required a liver transplantation and at least one death was reported.

What has been established about the possible connection to the SARS-CoV-2 virus, particularly as it relates to coinfection with adenovirus?

In that WHO report of 169 cases, adenovirus was detected in 74 and SARS-CoV-2 in 20. Of note, 19 cases had a SARS-CoV-2 and adenovirus coinfection.

The report’s authors emphasized that, “while adenovirus is a possible hypothesis, investigations are ongoing for the causative agent.” The authors questioned whether this represents a continuing increase in cases of hepatitis or reflects an increased awareness.

The stated priority of the WHO is to determine the cause and to further refine control and prevention actions.

Given the worldwide nature of this outbreak, have connections between any of the cases been made yet?

Not to my knowledge.
 

What clinicians need to know

What makes this outbreak of hepatitis cases particularly concerning to the health care community, in comparison to other childhood diseases that occur globally? Is it because the cause is unknown or is it for other reasons?

It may be a collective heightened concern following the emergence of COVID.

Whether it represents a new form of acute hepatitis, a continuing increase in cases of hepatitis, or an increased awareness because of the well-publicized alerts remains to be determined. We certainly saw “viral-induced hepatitis” in the past.

Young patients may first be brought to pediatricians. What, if anything, should pediatricians be on the lookout for? Do they need a heightened index of suspicion or are the cases too rare at this point?

An awareness of the “outbreak” may allow the clinician to extend the typical workup of a child presenting with an undefined, presumably viral illness.

In the cases reported, the prodromal and/or presenting symptoms were respiratory and gastrointestinal in nature. They include nausea, vomiting, diarrhea, and abdominal pain.

Specifically, if jaundice and/or scleral icterus is noted, then hepatitis should be suspected.

Should pediatricians consider early referral to a pediatric gastroenterologist or hepatologist?

Yes, because there is the potential for finding a treatable cause (for example, autoimmune hepatitis or a specific metabolic disease) in a patient presenting in this fashion.

In addition, the potential for progression to acute liver failure (with coagulopathy and encephalopathy), albeit rare, exists.

What do hepatologists need to be doing when presented with suspected cases?

The typical clinical picture holds and the workup is standard. The one new key, given the recent data, is to test for adenovirus, using whole blood versus plasma, as the former may be more sensitive.

In addition, it is prudent to check for SARS-CoV-2 by PCR.

What are the major questions that remain and that you’d like to see elucidated going forward?

There are many. Is this a new disease? A new variant of adenovirus? A synergy or susceptibility related to SARS-CoV-2? Is it related to a variant of SARS-CoV-2? Is it triggering an adverse immune response? Are there other epigenetic factors involved? And finally, is this an increase, or is it related to a collective heightened concern following the pandemic?

Dr. Balistreri is the Dorothy M.M. Kersten Professor of Pediatrics, director emeritus of the Pediatric Liver Care Center, medical director emeritus of liver transplantation, and professor at the University of Cincinnati; he is also with the department of pediatrics at Cincinnati Children’s Hospital Medical Center.

A version of this article first appeared on Medscape.com.