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Pathogenic bacteria worsen RSV severity, lengthen ICU stays in infants
WASHINGTON – Potentially pathogenic nasopharyngeal bacterial colonization was associated with more severe respiratory syncytial virus–related bronchiolitis in infants, according to a study.
"We found that [colonization] was significantly more common and almost double in the RSV patients, compared with controls," said Dr. Eleanora Bunsow, a researcher at Nationwide Children’s Hospital in Columbus, Ohio, who presented the data at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy. "And RSV patients were frequently colonized with more than one pathogenic bacteria."
Additionally, the use of polymerase chain reaction (PCR) assays to assess bacterial colonization types and levels was found to outperform the accuracy of cultures.
"The PCR showed an increased capacity for bacteria detection and had the ability to quantitate the bacterial load in infant RSV bronchiolitis," Dr. Bunsow said.
While the majority of infants hospitalized with RSV bronchiolitis are previously healthy with no known risk factors, about 15% will require intensive care. The role of pathogenic bacteria has, until recently, been explored only in animal studies, Dr. Bunsow said.
From December 2010 to May 2012, 294 children (median age, 2.5 years) were enrolled at a single site. Of these, 47 were age-matched healthy controls, 182 were inpatient, and 65 were admitted to the ICU. Both inpatient and ICU admissions tended to include twice as many boys as girls (1.6:1 and 1.7:1, respectively). A total of 47% of the control group were African Americans.
Cultures and PCR assays were performed on all study participants for the detection of gram-positive Staphylococcus aureus and Streptococcus pneumoniae, and gram-negative Moraxella catarrhalis and Haemophilus influenzae.
PCR had a 1.4-fold higher level of sensitivity (95% confidence interval, 91%-98%) and equal specificity when compared with cultures for identifying all four bacteria tested.
Polymicrobial bacterial colonization of both gram-positive and gram-negative species was found in 13% of RSV patients, compared with no potentially pathogenic bacterial colonizations in the control group (P = .004).
Rates of colonization were also higher in those with severe RSV infections of the lower respiratory tract who were admitted to the pediatric ICU (PICU), compared with inpatients with less severe disease (53.8% vs. 39%; P = .038). The median clinical disease severity score for those with potentially pathogenic bacterial colonization was 5, compared with a median score of 4 in those without colonization (P = .187).
Colonization with gram-negative bacteria was associated with a "significantly higher" need for up to 3 days of ICU oxygen support, compared with needing only up to 2 days of oxygen for colonization with gram-positive bacteria (P = .039), Dr. Bunsow noted.
Also, H. influenzae was identified in 54% of PICU patients, compared with 39% of inpatient ones. Higher H. influenzae loads correlated with PICU lengths of stay (P = .03).
"Our future study will include outpatients ... and will analyze the impact of the microbiome in these patients," Dr. Bunsow said.
Dr. Bunsow said she had no relevant disclosures.
On Twitter @whitneymcknight
This article highlights an observed association between severe RSV and colonization by pathogenic bacteria. Further investigations into this subgroup of RSV patients for aberrations in their innate immunity would be interesting. The article does not suggest that treatment of the bacteria would positively impact the clinical outcome of the affected patients.
This article highlights an observed association between severe RSV and colonization by pathogenic bacteria. Further investigations into this subgroup of RSV patients for aberrations in their innate immunity would be interesting. The article does not suggest that treatment of the bacteria would positively impact the clinical outcome of the affected patients.
This article highlights an observed association between severe RSV and colonization by pathogenic bacteria. Further investigations into this subgroup of RSV patients for aberrations in their innate immunity would be interesting. The article does not suggest that treatment of the bacteria would positively impact the clinical outcome of the affected patients.
WASHINGTON – Potentially pathogenic nasopharyngeal bacterial colonization was associated with more severe respiratory syncytial virus–related bronchiolitis in infants, according to a study.
"We found that [colonization] was significantly more common and almost double in the RSV patients, compared with controls," said Dr. Eleanora Bunsow, a researcher at Nationwide Children’s Hospital in Columbus, Ohio, who presented the data at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy. "And RSV patients were frequently colonized with more than one pathogenic bacteria."
Additionally, the use of polymerase chain reaction (PCR) assays to assess bacterial colonization types and levels was found to outperform the accuracy of cultures.
"The PCR showed an increased capacity for bacteria detection and had the ability to quantitate the bacterial load in infant RSV bronchiolitis," Dr. Bunsow said.
While the majority of infants hospitalized with RSV bronchiolitis are previously healthy with no known risk factors, about 15% will require intensive care. The role of pathogenic bacteria has, until recently, been explored only in animal studies, Dr. Bunsow said.
From December 2010 to May 2012, 294 children (median age, 2.5 years) were enrolled at a single site. Of these, 47 were age-matched healthy controls, 182 were inpatient, and 65 were admitted to the ICU. Both inpatient and ICU admissions tended to include twice as many boys as girls (1.6:1 and 1.7:1, respectively). A total of 47% of the control group were African Americans.
Cultures and PCR assays were performed on all study participants for the detection of gram-positive Staphylococcus aureus and Streptococcus pneumoniae, and gram-negative Moraxella catarrhalis and Haemophilus influenzae.
PCR had a 1.4-fold higher level of sensitivity (95% confidence interval, 91%-98%) and equal specificity when compared with cultures for identifying all four bacteria tested.
Polymicrobial bacterial colonization of both gram-positive and gram-negative species was found in 13% of RSV patients, compared with no potentially pathogenic bacterial colonizations in the control group (P = .004).
Rates of colonization were also higher in those with severe RSV infections of the lower respiratory tract who were admitted to the pediatric ICU (PICU), compared with inpatients with less severe disease (53.8% vs. 39%; P = .038). The median clinical disease severity score for those with potentially pathogenic bacterial colonization was 5, compared with a median score of 4 in those without colonization (P = .187).
Colonization with gram-negative bacteria was associated with a "significantly higher" need for up to 3 days of ICU oxygen support, compared with needing only up to 2 days of oxygen for colonization with gram-positive bacteria (P = .039), Dr. Bunsow noted.
Also, H. influenzae was identified in 54% of PICU patients, compared with 39% of inpatient ones. Higher H. influenzae loads correlated with PICU lengths of stay (P = .03).
"Our future study will include outpatients ... and will analyze the impact of the microbiome in these patients," Dr. Bunsow said.
Dr. Bunsow said she had no relevant disclosures.
On Twitter @whitneymcknight
WASHINGTON – Potentially pathogenic nasopharyngeal bacterial colonization was associated with more severe respiratory syncytial virus–related bronchiolitis in infants, according to a study.
"We found that [colonization] was significantly more common and almost double in the RSV patients, compared with controls," said Dr. Eleanora Bunsow, a researcher at Nationwide Children’s Hospital in Columbus, Ohio, who presented the data at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy. "And RSV patients were frequently colonized with more than one pathogenic bacteria."
Additionally, the use of polymerase chain reaction (PCR) assays to assess bacterial colonization types and levels was found to outperform the accuracy of cultures.
"The PCR showed an increased capacity for bacteria detection and had the ability to quantitate the bacterial load in infant RSV bronchiolitis," Dr. Bunsow said.
While the majority of infants hospitalized with RSV bronchiolitis are previously healthy with no known risk factors, about 15% will require intensive care. The role of pathogenic bacteria has, until recently, been explored only in animal studies, Dr. Bunsow said.
From December 2010 to May 2012, 294 children (median age, 2.5 years) were enrolled at a single site. Of these, 47 were age-matched healthy controls, 182 were inpatient, and 65 were admitted to the ICU. Both inpatient and ICU admissions tended to include twice as many boys as girls (1.6:1 and 1.7:1, respectively). A total of 47% of the control group were African Americans.
Cultures and PCR assays were performed on all study participants for the detection of gram-positive Staphylococcus aureus and Streptococcus pneumoniae, and gram-negative Moraxella catarrhalis and Haemophilus influenzae.
PCR had a 1.4-fold higher level of sensitivity (95% confidence interval, 91%-98%) and equal specificity when compared with cultures for identifying all four bacteria tested.
Polymicrobial bacterial colonization of both gram-positive and gram-negative species was found in 13% of RSV patients, compared with no potentially pathogenic bacterial colonizations in the control group (P = .004).
Rates of colonization were also higher in those with severe RSV infections of the lower respiratory tract who were admitted to the pediatric ICU (PICU), compared with inpatients with less severe disease (53.8% vs. 39%; P = .038). The median clinical disease severity score for those with potentially pathogenic bacterial colonization was 5, compared with a median score of 4 in those without colonization (P = .187).
Colonization with gram-negative bacteria was associated with a "significantly higher" need for up to 3 days of ICU oxygen support, compared with needing only up to 2 days of oxygen for colonization with gram-positive bacteria (P = .039), Dr. Bunsow noted.
Also, H. influenzae was identified in 54% of PICU patients, compared with 39% of inpatient ones. Higher H. influenzae loads correlated with PICU lengths of stay (P = .03).
"Our future study will include outpatients ... and will analyze the impact of the microbiome in these patients," Dr. Bunsow said.
Dr. Bunsow said she had no relevant disclosures.
On Twitter @whitneymcknight
AT ICAAC 2014
Key clinical point: Nasopharyngeal colonization with pathogenic bacteria worsens the course of RVS in infants.
Major finding: Polymicrobial bacterial colonization was found in 13% of pediatric patients admitted for RSV, compared with 0% of healthy controls.
Data source: Prospective, single-site study of 247 RSV patients and 47 age-matched healthy controls.
Disclosures: Dr. Bunsow said she had no relevant disclosures.
Studies point to potential for huge HCV rise in MSM
WASHINGTON – Two studies of men having sex with men suggest that hepatitis C transmission in that group might be on the cusp of a big increase, in part because of risky behavior such as unprotected anal intercourse and injection drug use.
One study was conducted among MSM in Switzerland, while another was a retrospective look at HIV-negative men in several sexual health clinics across London.
In the Swiss study, researchers wanted to assess knowledge of HCV in MSM and also the prevalence of HCV in a local population. Regular screening for HCV in the MSM population was recommended by the European AIDS Clinical Society in June, but actual screening and knowledge is thought to be low, said Dr. Matthias Cavassini of Lausanne (Switzerland) Hospital.
He and his colleagues approached 918 MSM from June 2011 to August 2012 and asked them to participate in an anonymous questionnaire and, subsequently, to undergo HCV testing. Seventy-one percent – 654 – agreed. The vast majority who agreed – 82% – had been approached at a clinic for MSM that screens for sexually transmitted illnesses. The rest came from a sauna (13%), sex clubs (3.2%), a gay pride event (1.4%), and parks (0.3%).
The median age was 33; 512 identified as homosexual (78%) and 140 as bisexual (21%). Most (431) were HIV negative, although 62 preferred not to disclose HIV status. The median number of sexual partners was 5; the range was 0 to 400. Fifty-two percent (337) had a history of STI screening within the past year. When asked about HCV screening, 154 said they’d been tested, while 380 (58%) said they did not know.
Fifty-five percent (357) had unprotected anal intercourse – a primary HCV risk factor – in the past year. Thirty-three percent (219) had a history of drug use or were current users, but only four (0.6%) reported injection drug use.
Half had no knowledge about HCV. Of the 302 who did report knowledge, a striking 84% said they were aware that HCV could be transmitted through anal sex. Only 26% knew that it could not be transmitted through oral sex. There seemed to be no particular factor that predicted knowledge.
Of the 654 who consented to HCV screening, only one (0.15%) tested positive, said Dr. Cavassini. The man’s primary risk factor was unprotected anal intercourse in the previous year.
One case does not make an epidemic, but the high prevalence of unprotected anal intercourse argues for screening in the MSM population, he said. "Is this an accident waiting to happen?" asked Dr. Cavassini.
The British study was conducted by Dr. Katie McFaul and her colleagues at Chelsea and Westminster Hospital. They retrospectively reviewed charts for all HIV-negative MSM at three clinics between Jan. 2010 and May 2014, and identified just 44 who met the criteria for acute HCV.
Of those, 15 had a previous negative HCV test within the past year, 11 had significant ALT elevation, and 18 were clinically diagnosed with HCV from risk exposure, history, and symptoms. The median age was 37, and the median number of partners was 2, with a range of 1 to 100.
Looking more closely at behavior, Dr. McFaul found that 82% reported that they engaged in unprotected anal intercourse. Many also engaged in equally risky behavior, including group sex (28%), fisting (25%), or using drugs during sex, with about 20% of those reporting injection drug use.
Of the 44 with HCV, 29 knew the status of their partner or partners; 2 had a partner with HCV, 13 had a partner with HIV, and 6 had a partner with HIV and HCV. Thirteen had an STI at the time of HCV diagnosis.
Eight had received postexposure prophylaxis for HIV before their HCV diagnosis. Overall, 15 of the 44 had a spontaneous clearance of the HCV. Eleven received treatment. Eleven percent were lost to follow-up and 30% are being observed.
While HCV prevalence seemed low, it is likely not accurate, said Dr. McFaul, noting that she and her colleagues found that HCV screening in HIV-negative MSM was rarely conducted. A one-month snapshot at the three clinics found that 15% (565) of 3,811 HIV negative men who came for sexual health screening were tested.
Extrapolating the data to all 623,350 visits during the 2010-2014 study period, Dr. McFaul estimated that about 261,036 HIV-negative MSM visited. At the current 15% screening rate, 34,657 would have been screened for HCV. But that means that almost 200,000 were not screened for HCV.
"We suggest that hepatitis C screening should be performed at routine sexual health screening, particularly in individuals with risk factors, and in environments where there is a high hepatitis C prevalence," she said. Clinicians also "need to ask penetrating questions about penetrating activities.
"If you don’t take a temperature you won’t find a fever," she said. "I think we’ll find a higher prevalence then we currently see."
On Twitter @aliciaault
WASHINGTON – Two studies of men having sex with men suggest that hepatitis C transmission in that group might be on the cusp of a big increase, in part because of risky behavior such as unprotected anal intercourse and injection drug use.
One study was conducted among MSM in Switzerland, while another was a retrospective look at HIV-negative men in several sexual health clinics across London.
In the Swiss study, researchers wanted to assess knowledge of HCV in MSM and also the prevalence of HCV in a local population. Regular screening for HCV in the MSM population was recommended by the European AIDS Clinical Society in June, but actual screening and knowledge is thought to be low, said Dr. Matthias Cavassini of Lausanne (Switzerland) Hospital.
He and his colleagues approached 918 MSM from June 2011 to August 2012 and asked them to participate in an anonymous questionnaire and, subsequently, to undergo HCV testing. Seventy-one percent – 654 – agreed. The vast majority who agreed – 82% – had been approached at a clinic for MSM that screens for sexually transmitted illnesses. The rest came from a sauna (13%), sex clubs (3.2%), a gay pride event (1.4%), and parks (0.3%).
The median age was 33; 512 identified as homosexual (78%) and 140 as bisexual (21%). Most (431) were HIV negative, although 62 preferred not to disclose HIV status. The median number of sexual partners was 5; the range was 0 to 400. Fifty-two percent (337) had a history of STI screening within the past year. When asked about HCV screening, 154 said they’d been tested, while 380 (58%) said they did not know.
Fifty-five percent (357) had unprotected anal intercourse – a primary HCV risk factor – in the past year. Thirty-three percent (219) had a history of drug use or were current users, but only four (0.6%) reported injection drug use.
Half had no knowledge about HCV. Of the 302 who did report knowledge, a striking 84% said they were aware that HCV could be transmitted through anal sex. Only 26% knew that it could not be transmitted through oral sex. There seemed to be no particular factor that predicted knowledge.
Of the 654 who consented to HCV screening, only one (0.15%) tested positive, said Dr. Cavassini. The man’s primary risk factor was unprotected anal intercourse in the previous year.
One case does not make an epidemic, but the high prevalence of unprotected anal intercourse argues for screening in the MSM population, he said. "Is this an accident waiting to happen?" asked Dr. Cavassini.
The British study was conducted by Dr. Katie McFaul and her colleagues at Chelsea and Westminster Hospital. They retrospectively reviewed charts for all HIV-negative MSM at three clinics between Jan. 2010 and May 2014, and identified just 44 who met the criteria for acute HCV.
Of those, 15 had a previous negative HCV test within the past year, 11 had significant ALT elevation, and 18 were clinically diagnosed with HCV from risk exposure, history, and symptoms. The median age was 37, and the median number of partners was 2, with a range of 1 to 100.
Looking more closely at behavior, Dr. McFaul found that 82% reported that they engaged in unprotected anal intercourse. Many also engaged in equally risky behavior, including group sex (28%), fisting (25%), or using drugs during sex, with about 20% of those reporting injection drug use.
Of the 44 with HCV, 29 knew the status of their partner or partners; 2 had a partner with HCV, 13 had a partner with HIV, and 6 had a partner with HIV and HCV. Thirteen had an STI at the time of HCV diagnosis.
Eight had received postexposure prophylaxis for HIV before their HCV diagnosis. Overall, 15 of the 44 had a spontaneous clearance of the HCV. Eleven received treatment. Eleven percent were lost to follow-up and 30% are being observed.
While HCV prevalence seemed low, it is likely not accurate, said Dr. McFaul, noting that she and her colleagues found that HCV screening in HIV-negative MSM was rarely conducted. A one-month snapshot at the three clinics found that 15% (565) of 3,811 HIV negative men who came for sexual health screening were tested.
Extrapolating the data to all 623,350 visits during the 2010-2014 study period, Dr. McFaul estimated that about 261,036 HIV-negative MSM visited. At the current 15% screening rate, 34,657 would have been screened for HCV. But that means that almost 200,000 were not screened for HCV.
"We suggest that hepatitis C screening should be performed at routine sexual health screening, particularly in individuals with risk factors, and in environments where there is a high hepatitis C prevalence," she said. Clinicians also "need to ask penetrating questions about penetrating activities.
"If you don’t take a temperature you won’t find a fever," she said. "I think we’ll find a higher prevalence then we currently see."
On Twitter @aliciaault
WASHINGTON – Two studies of men having sex with men suggest that hepatitis C transmission in that group might be on the cusp of a big increase, in part because of risky behavior such as unprotected anal intercourse and injection drug use.
One study was conducted among MSM in Switzerland, while another was a retrospective look at HIV-negative men in several sexual health clinics across London.
In the Swiss study, researchers wanted to assess knowledge of HCV in MSM and also the prevalence of HCV in a local population. Regular screening for HCV in the MSM population was recommended by the European AIDS Clinical Society in June, but actual screening and knowledge is thought to be low, said Dr. Matthias Cavassini of Lausanne (Switzerland) Hospital.
He and his colleagues approached 918 MSM from June 2011 to August 2012 and asked them to participate in an anonymous questionnaire and, subsequently, to undergo HCV testing. Seventy-one percent – 654 – agreed. The vast majority who agreed – 82% – had been approached at a clinic for MSM that screens for sexually transmitted illnesses. The rest came from a sauna (13%), sex clubs (3.2%), a gay pride event (1.4%), and parks (0.3%).
The median age was 33; 512 identified as homosexual (78%) and 140 as bisexual (21%). Most (431) were HIV negative, although 62 preferred not to disclose HIV status. The median number of sexual partners was 5; the range was 0 to 400. Fifty-two percent (337) had a history of STI screening within the past year. When asked about HCV screening, 154 said they’d been tested, while 380 (58%) said they did not know.
Fifty-five percent (357) had unprotected anal intercourse – a primary HCV risk factor – in the past year. Thirty-three percent (219) had a history of drug use or were current users, but only four (0.6%) reported injection drug use.
Half had no knowledge about HCV. Of the 302 who did report knowledge, a striking 84% said they were aware that HCV could be transmitted through anal sex. Only 26% knew that it could not be transmitted through oral sex. There seemed to be no particular factor that predicted knowledge.
Of the 654 who consented to HCV screening, only one (0.15%) tested positive, said Dr. Cavassini. The man’s primary risk factor was unprotected anal intercourse in the previous year.
One case does not make an epidemic, but the high prevalence of unprotected anal intercourse argues for screening in the MSM population, he said. "Is this an accident waiting to happen?" asked Dr. Cavassini.
The British study was conducted by Dr. Katie McFaul and her colleagues at Chelsea and Westminster Hospital. They retrospectively reviewed charts for all HIV-negative MSM at three clinics between Jan. 2010 and May 2014, and identified just 44 who met the criteria for acute HCV.
Of those, 15 had a previous negative HCV test within the past year, 11 had significant ALT elevation, and 18 were clinically diagnosed with HCV from risk exposure, history, and symptoms. The median age was 37, and the median number of partners was 2, with a range of 1 to 100.
Looking more closely at behavior, Dr. McFaul found that 82% reported that they engaged in unprotected anal intercourse. Many also engaged in equally risky behavior, including group sex (28%), fisting (25%), or using drugs during sex, with about 20% of those reporting injection drug use.
Of the 44 with HCV, 29 knew the status of their partner or partners; 2 had a partner with HCV, 13 had a partner with HIV, and 6 had a partner with HIV and HCV. Thirteen had an STI at the time of HCV diagnosis.
Eight had received postexposure prophylaxis for HIV before their HCV diagnosis. Overall, 15 of the 44 had a spontaneous clearance of the HCV. Eleven received treatment. Eleven percent were lost to follow-up and 30% are being observed.
While HCV prevalence seemed low, it is likely not accurate, said Dr. McFaul, noting that she and her colleagues found that HCV screening in HIV-negative MSM was rarely conducted. A one-month snapshot at the three clinics found that 15% (565) of 3,811 HIV negative men who came for sexual health screening were tested.
Extrapolating the data to all 623,350 visits during the 2010-2014 study period, Dr. McFaul estimated that about 261,036 HIV-negative MSM visited. At the current 15% screening rate, 34,657 would have been screened for HCV. But that means that almost 200,000 were not screened for HCV.
"We suggest that hepatitis C screening should be performed at routine sexual health screening, particularly in individuals with risk factors, and in environments where there is a high hepatitis C prevalence," she said. Clinicians also "need to ask penetrating questions about penetrating activities.
"If you don’t take a temperature you won’t find a fever," she said. "I think we’ll find a higher prevalence then we currently see."
On Twitter @aliciaault
FROM ICAAC 2014
Key clinical point: Physicians should ask men who have sex with men very specific questions about sexual activity and injection drug use.
Major finding: Half to a majority of MSM in two studies engaged in unprotected anal intercourse, a primary risk factor for HCV transmission.
Data source: A prospective survey of MSM in Switzerland and a retrospective review of HIV-negative MSM in London.
Disclosures: Dr. Cavassini received travel grants from Bristol-Myers Squibb, Boehringer-Ingelheim, and Gilead. Dr. McFaul reported no conflicts. The studies were sponsored by their respective institutions.
May-July epidemic of RSV highest in infants, study shows
WASHINGTON – Respiratory syncytial virus followed an epidemic pattern, particularly in infants, from May through July across 13 years, a study has shown.
The virus also was found more often in infants less than 3 months old who had bronchiolitis or hypoxemia at time of hospital admission, according to Dr. Maria F. Lucion, who presented the data during the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.
"This is a really valuable study with a very large number of cases. We don’t have a lot of information on this virus." Dr. Keith Klugman, director of global health at the Bill and Melinda Gates Foundation, Seattle, said during the discussion after the presentation.
From March 2000 to November 2013, 12,555 patients admitted for suspected acute lower respiratory infections to a single center in Argentina were tested for respiratory syncytial virus (RSV), adenovirus, influenza, and parainfluenza using either assays of nasopharyngeal aspirates or real-time polymerase chain reaction.
Of the 4,798 patients who tested positive for infection, 3,924 of all those admitted were found to have RSV (ranging between 71% and 82% across the years), with an annual seasonal epidemic pattern in evidence from May through July.
Independent predictors of RSV included being 3 months or younger (odds ratio 2.8, P less than .01); having bronchiolitis as a clinical presentation (OR 1.54, P less than .01); and the presence of hypoxemia at time of admission (OR 1.84, P less than .01), said Dr. Lucion of Ricardo Gutierrez Children’s Hospital, Buenos Aires.
The overall hospitalization rate for those with bronchiolitis was 39 per 1,000, with a peak in 2003 of 48 per 1,000. Bronchiolitis as a result of RSV was diagnosed in a median 15 patients per 1,000 (8.0-19.4).
The majority of admissions were male (56%), and the median age was 7 months, although nearly half (43%) were less than 6 months old (74.2% were less than 1 year old). Bronchiolitis occurred 61% of the time, and the nosocomial infection rate was 6.6%. The mortality rate was just under 2% (74/3,888).
"The most frequent complication was respiratory distress requiring the use of a ventilator," Dr. Lucion said. "That was most associated with the children who died."
An additional genetic analysis indicated that RSV subtypes A and B were in the pediatric population, with the exceptions of 2000 when only subtype A was present, and 2005, when only subtype B was present.
"The most common genotypes were GA2, GA5, ON1, and NA1 for subtype A and genotype-BA for subtype B," Dr. Lucion said.
Dr. Lucion said she had no relevant disclosures.
On Twitter @whitneymcknight
WASHINGTON – Respiratory syncytial virus followed an epidemic pattern, particularly in infants, from May through July across 13 years, a study has shown.
The virus also was found more often in infants less than 3 months old who had bronchiolitis or hypoxemia at time of hospital admission, according to Dr. Maria F. Lucion, who presented the data during the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.
"This is a really valuable study with a very large number of cases. We don’t have a lot of information on this virus." Dr. Keith Klugman, director of global health at the Bill and Melinda Gates Foundation, Seattle, said during the discussion after the presentation.
From March 2000 to November 2013, 12,555 patients admitted for suspected acute lower respiratory infections to a single center in Argentina were tested for respiratory syncytial virus (RSV), adenovirus, influenza, and parainfluenza using either assays of nasopharyngeal aspirates or real-time polymerase chain reaction.
Of the 4,798 patients who tested positive for infection, 3,924 of all those admitted were found to have RSV (ranging between 71% and 82% across the years), with an annual seasonal epidemic pattern in evidence from May through July.
Independent predictors of RSV included being 3 months or younger (odds ratio 2.8, P less than .01); having bronchiolitis as a clinical presentation (OR 1.54, P less than .01); and the presence of hypoxemia at time of admission (OR 1.84, P less than .01), said Dr. Lucion of Ricardo Gutierrez Children’s Hospital, Buenos Aires.
The overall hospitalization rate for those with bronchiolitis was 39 per 1,000, with a peak in 2003 of 48 per 1,000. Bronchiolitis as a result of RSV was diagnosed in a median 15 patients per 1,000 (8.0-19.4).
The majority of admissions were male (56%), and the median age was 7 months, although nearly half (43%) were less than 6 months old (74.2% were less than 1 year old). Bronchiolitis occurred 61% of the time, and the nosocomial infection rate was 6.6%. The mortality rate was just under 2% (74/3,888).
"The most frequent complication was respiratory distress requiring the use of a ventilator," Dr. Lucion said. "That was most associated with the children who died."
An additional genetic analysis indicated that RSV subtypes A and B were in the pediatric population, with the exceptions of 2000 when only subtype A was present, and 2005, when only subtype B was present.
"The most common genotypes were GA2, GA5, ON1, and NA1 for subtype A and genotype-BA for subtype B," Dr. Lucion said.
Dr. Lucion said she had no relevant disclosures.
On Twitter @whitneymcknight
WASHINGTON – Respiratory syncytial virus followed an epidemic pattern, particularly in infants, from May through July across 13 years, a study has shown.
The virus also was found more often in infants less than 3 months old who had bronchiolitis or hypoxemia at time of hospital admission, according to Dr. Maria F. Lucion, who presented the data during the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.
"This is a really valuable study with a very large number of cases. We don’t have a lot of information on this virus." Dr. Keith Klugman, director of global health at the Bill and Melinda Gates Foundation, Seattle, said during the discussion after the presentation.
From March 2000 to November 2013, 12,555 patients admitted for suspected acute lower respiratory infections to a single center in Argentina were tested for respiratory syncytial virus (RSV), adenovirus, influenza, and parainfluenza using either assays of nasopharyngeal aspirates or real-time polymerase chain reaction.
Of the 4,798 patients who tested positive for infection, 3,924 of all those admitted were found to have RSV (ranging between 71% and 82% across the years), with an annual seasonal epidemic pattern in evidence from May through July.
Independent predictors of RSV included being 3 months or younger (odds ratio 2.8, P less than .01); having bronchiolitis as a clinical presentation (OR 1.54, P less than .01); and the presence of hypoxemia at time of admission (OR 1.84, P less than .01), said Dr. Lucion of Ricardo Gutierrez Children’s Hospital, Buenos Aires.
The overall hospitalization rate for those with bronchiolitis was 39 per 1,000, with a peak in 2003 of 48 per 1,000. Bronchiolitis as a result of RSV was diagnosed in a median 15 patients per 1,000 (8.0-19.4).
The majority of admissions were male (56%), and the median age was 7 months, although nearly half (43%) were less than 6 months old (74.2% were less than 1 year old). Bronchiolitis occurred 61% of the time, and the nosocomial infection rate was 6.6%. The mortality rate was just under 2% (74/3,888).
"The most frequent complication was respiratory distress requiring the use of a ventilator," Dr. Lucion said. "That was most associated with the children who died."
An additional genetic analysis indicated that RSV subtypes A and B were in the pediatric population, with the exceptions of 2000 when only subtype A was present, and 2005, when only subtype B was present.
"The most common genotypes were GA2, GA5, ON1, and NA1 for subtype A and genotype-BA for subtype B," Dr. Lucion said.
Dr. Lucion said she had no relevant disclosures.
On Twitter @whitneymcknight
AT ICAAC 2014
Key clinical point: Infants less than 3 months old who had RSV tended to present with bronchiolitis or hypoxemia at the time of admission.
Major finding: Forty-three percent of patients with acute lower respiratory infection who tested positive for the respiratory syncytial virus were infants under the age of 7 months, with highest rates occurring May through July (P less than .001).
Data source: A prospective cohort study of 12,555 patients in Argentina admitted for acute lower respiratory infection between 2000 and 2013.
Disclosures: Dr. Lucion said she had no relevant disclosures.
