CDC Updates Infant GBS Prevention Guide

The incidence of group B streptococcal disease in infants has declined sharply since guidelines for prevention were implemented nearly 15 years ago, but GBS nonetheless remains the leading infectious cause of morbidity and mortality among infants in the United States, according to the Centers for Disease Control and Prevention, which recently updated the guidelines to further promote prevention efforts.

Since the guidelines were first published by the CDC in 1996 – then updated and republished in 2002 – the number of cases per 1,000 live births has declined from 1.7 to 0.34-0.37. Universal screening at 35–37 weeks' gestation and the use of intrapartum antibiotic prophylaxis as recommended in the original and updated guidelines is credited for this improvement, but the rates of maternal colonization, and therefore the risk of early-onset disease in the absence of intrapartum antibiotic prophylaxis, has remained unchanged since the 1970s.

“The continued burden of disease and newly available data relevant to early-onset GBS disease prevention from the fields of epidemiology, obstetrics, neonatology, microbiology, molecular biology, and pharmacology prompted revision of the guidelines for early-onset GBS disease prevention,” according to the CDC's report introducing the most recently revised guidelines (MMWR 2010;59[RR-10]:1–32).

A technical working group, which was formed to review and update the guidelines, identified a subset of topics for review, then revised the guidelines based on available evidence and expert opinion. Changes were made regarding both secondary prevention in newborns and maternal prophylaxis.

In large part, the revised guidelines are reaffirmation of the earlier guidelines, according to Dr. Carol Baker, professor of pediatrics, molecular virology, and microbiology at the Baylor College of Medicine, Houston, and a member of the technical working group charged with updating the guidelines.

“All women who are pregnant should be screened with cultures at 35–37 weeks. That's the main strategy to prevent early-onset disease in babies, and it hasn't changed one bit,” she said in an interview.

There was, however, some “tweaking” of the existing guidelines to simplify and clarify processes, add some new information about alternative laboratory methods for testing, and provide for alternative treatments – for example, for women allergic to penicillin, she said.

As for secondary prevention in neonates, a management algorithm for secondary GBS prevention, which is designed to detect potential cases as early as possible, remained mostly the same, except it was streamlined and now applies to all newborns.

Although the changes in the guidelines are generally small when it comes to secondary prevention in infants, they are important, and taken together, the changes for both mothers and babies are expected to provide some incremental improvements in outcome, Dr. Baker said.

The good news is there is 80% less early-onset GBS disease than there was before the culture screening recommendations came out in 1996, and that's real progress, she said, adding that there is room for improvement – particularly in late-onset disease, which hasn't changed much.

“We can probably do a little better with these [updated guidelines],” she said.

However, until the pharmaceutical industry moves forward with the available vaccine science and develops a GBS vaccine, it is doubtful much progress will be made in regard to late-onset disease, Dr. Baker said, noting that she believes the industry has failed to act on that science out of fear of the litigation so commonplace in obstetrics and maternal-fetal medicine.

Still, progress is being made, and good compliance with the guidelines is expected, particularly since the updated guidelines have been endorsed by the American Academy of Pediatrics, the American College of Obstetricians and Gynecologists, the American College of Nurse-Midwives, the American Academy of Family Physicians, and the American Society for Microbiology. All have had a hand in developing the guidelines, and thus have a stake in the outcomes, she noted.

“I'm very optimistic that there will be high compliance both on the baby side and the mother's side. It's a matter of education – hopefully the news will get out,” Dr. Baker said.

Indeed, the guidelines call for local and state public health agencies, in conjunction with hospitals, to establish surveillance for early-onset GBS, and to “take other steps to promote perinatal GBS disease prevention and education to reduce the incidence of early onset GBS disease in their states.”

The algorithm calls for a full diagnostic evaluation in all newborns with signs of sepsis, as well as provision of antibiotics active against GBS and other organisms that might cause sepsis pending the results of the evaluation. The evaluation should include “a blood culture; a CBC including white blood cell differential and platelet count; a chest radiograph if any abnormal respiratory signs are present; and a lumbar puncture if the newborn is stable enough to tolerate the procedure and sepsis is suspected,” according to the guidelines.

Also, well-appearing newborns whose mothers had suspected chorioamnionitis should undergo a limited evaluation (blood culture and CBC as above, but no chest x-ray or lumbar puncture is necessary) and should receive antibiotic treatment pending culture results. Well-appearing infants whose mothers had no chorioamnionitis and no indication for GBS prophylaxis should be managed according to routine clinical care.

Other key components of the algorithm call for the following:

▸ Observation for at least 48 hours – but no routine diagnostic testing – in well-appearing infants of any gestational age whose mother received adequate intrapartum GBS prophylaxis (clarified in the newly revised guidelines to be at least 4 hours of intravenous penicillin, ampicillin, or cefazolin before delivery). Observation now is also recommended in well-appearing infants born to mothers who had an indication for GBS prophylaxis but received no or inadequate prophylaxis, as long as the infant is at least 37 weeks' gestational age, and the duration of membrane rupture before delivery was less than 18 hours.

▸ Limited evaluation and observation for at least 48 hours in well-appearing infants born to mothers with an indication for prophylaxis, but who received no or inadequate prophylaxis, when the infant is less than 37 weeks' gestation or duration of membrane rupture before delivery was 18 hours or more.

Well-appearing infants with a gestational age of 35–36 weeks whose mothers received adequate intrapartum antibiotic prophylaxis do not routinely require diagnostic evaluations.

In addition to these steps, research aimed at better understanding the racial and ethnic differences that still persist in GBS disease incidence is needed, according to the CDC report. Research is needed on strategies for preventing early-onset disease among preterm infants, the role of bacteriuria as a risk factor, effectiveness of the recommended intrapartum antibiotic prophylaxis agents for penicillin-allergic women at high risk for anaphylaxis, the impact and effectiveness of recommendations for secondary prevention of early-onset disease among neonates, and factors contributing to the higher than anticipated proportion of early-onset GBS disease cases occurring among infants born to women with negative prenatal GBS screens. Such ongoing research is important because, in the absence of a licensed GBS vaccine, universal screening and intrapartum antibiotic prophylaxis continue to be the cornerstones of prevention, the report states.

“I'm very optimistic that there will be high compliance both on the baby side and the mother's side,” Dr. Carol Baker said.

Source Courtesy Marcia A. Rench

The incidence of group B streptococcal disease in infants has declined sharply since guidelines for prevention were implemented nearly 15 years ago, but GBS nonetheless remains the leading infectious cause of morbidity and mortality among infants in the United States, according to the Centers for Disease Control and Prevention, which recently updated the guidelines to further promote prevention efforts.

Since the guidelines were first published by the CDC in 1996 – then updated and republished in 2002 – the number of cases per 1,000 live births has declined from 1.7 to 0.34-0.37. Universal screening at 35–37 weeks' gestation and the use of intrapartum antibiotic prophylaxis as recommended in the original and updated guidelines is credited for this improvement, but the rates of maternal colonization, and therefore the risk of early-onset disease in the absence of intrapartum antibiotic prophylaxis, has remained unchanged since the 1970s.

“The continued burden of disease and newly available data relevant to early-onset GBS disease prevention from the fields of epidemiology, obstetrics, neonatology, microbiology, molecular biology, and pharmacology prompted revision of the guidelines for early-onset GBS disease prevention,” according to the CDC's report introducing the most recently revised guidelines (MMWR 2010;59[RR-10]:1–32).

A technical working group, which was formed to review and update the guidelines, identified a subset of topics for review, then revised the guidelines based on available evidence and expert opinion. Changes were made regarding both secondary prevention in newborns and maternal prophylaxis.

In large part, the revised guidelines are reaffirmation of the earlier guidelines, according to Dr. Carol Baker, professor of pediatrics, molecular virology, and microbiology at the Baylor College of Medicine, Houston, and a member of the technical working group charged with updating the guidelines.

“All women who are pregnant should be screened with cultures at 35–37 weeks. That's the main strategy to prevent early-onset disease in babies, and it hasn't changed one bit,” she said in an interview.

There was, however, some “tweaking” of the existing guidelines to simplify and clarify processes, add some new information about alternative laboratory methods for testing, and provide for alternative treatments – for example, for women allergic to penicillin, she said.

As for secondary prevention in neonates, a management algorithm for secondary GBS prevention, which is designed to detect potential cases as early as possible, remained mostly the same, except it was streamlined and now applies to all newborns.

Although the changes in the guidelines are generally small when it comes to secondary prevention in infants, they are important, and taken together, the changes for both mothers and babies are expected to provide some incremental improvements in outcome, Dr. Baker said.

The good news is there is 80% less early-onset GBS disease than there was before the culture screening recommendations came out in 1996, and that's real progress, she said, adding that there is room for improvement – particularly in late-onset disease, which hasn't changed much.

“We can probably do a little better with these [updated guidelines],” she said.

However, until the pharmaceutical industry moves forward with the available vaccine science and develops a GBS vaccine, it is doubtful much progress will be made in regard to late-onset disease, Dr. Baker said, noting that she believes the industry has failed to act on that science out of fear of the litigation so commonplace in obstetrics and maternal-fetal medicine.

Still, progress is being made, and good compliance with the guidelines is expected, particularly since the updated guidelines have been endorsed by the American Academy of Pediatrics, the American College of Obstetricians and Gynecologists, the American College of Nurse-Midwives, the American Academy of Family Physicians, and the American Society for Microbiology. All have had a hand in developing the guidelines, and thus have a stake in the outcomes, she noted.

“I'm very optimistic that there will be high compliance both on the baby side and the mother's side. It's a matter of education – hopefully the news will get out,” Dr. Baker said.

Indeed, the guidelines call for local and state public health agencies, in conjunction with hospitals, to establish surveillance for early-onset GBS, and to “take other steps to promote perinatal GBS disease prevention and education to reduce the incidence of early onset GBS disease in their states.”

The algorithm calls for a full diagnostic evaluation in all newborns with signs of sepsis, as well as provision of antibiotics active against GBS and other organisms that might cause sepsis pending the results of the evaluation. The evaluation should include “a blood culture; a CBC including white blood cell differential and platelet count; a chest radiograph if any abnormal respiratory signs are present; and a lumbar puncture if the newborn is stable enough to tolerate the procedure and sepsis is suspected,” according to the guidelines.

Also, well-appearing newborns whose mothers had suspected chorioamnionitis should undergo a limited evaluation (blood culture and CBC as above, but no chest x-ray or lumbar puncture is necessary) and should receive antibiotic treatment pending culture results. Well-appearing infants whose mothers had no chorioamnionitis and no indication for GBS prophylaxis should be managed according to routine clinical care.

Other key components of the algorithm call for the following:

▸ Observation for at least 48 hours – but no routine diagnostic testing – in well-appearing infants of any gestational age whose mother received adequate intrapartum GBS prophylaxis (clarified in the newly revised guidelines to be at least 4 hours of intravenous penicillin, ampicillin, or cefazolin before delivery). Observation now is also recommended in well-appearing infants born to mothers who had an indication for GBS prophylaxis but received no or inadequate prophylaxis, as long as the infant is at least 37 weeks' gestational age, and the duration of membrane rupture before delivery was less than 18 hours.

▸ Limited evaluation and observation for at least 48 hours in well-appearing infants born to mothers with an indication for prophylaxis, but who received no or inadequate prophylaxis, when the infant is less than 37 weeks' gestation or duration of membrane rupture before delivery was 18 hours or more.

Well-appearing infants with a gestational age of 35–36 weeks whose mothers received adequate intrapartum antibiotic prophylaxis do not routinely require diagnostic evaluations.

In addition to these steps, research aimed at better understanding the racial and ethnic differences that still persist in GBS disease incidence is needed, according to the CDC report. Research is needed on strategies for preventing early-onset disease among preterm infants, the role of bacteriuria as a risk factor, effectiveness of the recommended intrapartum antibiotic prophylaxis agents for penicillin-allergic women at high risk for anaphylaxis, the impact and effectiveness of recommendations for secondary prevention of early-onset disease among neonates, and factors contributing to the higher than anticipated proportion of early-onset GBS disease cases occurring among infants born to women with negative prenatal GBS screens. Such ongoing research is important because, in the absence of a licensed GBS vaccine, universal screening and intrapartum antibiotic prophylaxis continue to be the cornerstones of prevention, the report states.

“I'm very optimistic that there will be high compliance both on the baby side and the mother's side,” Dr. Carol Baker said.

Source Courtesy Marcia A. Rench

The incidence of group B streptococcal disease in infants has declined sharply since guidelines for prevention were implemented nearly 15 years ago, but GBS nonetheless remains the leading infectious cause of morbidity and mortality among infants in the United States, according to the Centers for Disease Control and Prevention, which recently updated the guidelines to further promote prevention efforts.

Since the guidelines were first published by the CDC in 1996 – then updated and republished in 2002 – the number of cases per 1,000 live births has declined from 1.7 to 0.34-0.37. Universal screening at 35–37 weeks' gestation and the use of intrapartum antibiotic prophylaxis as recommended in the original and updated guidelines is credited for this improvement, but the rates of maternal colonization, and therefore the risk of early-onset disease in the absence of intrapartum antibiotic prophylaxis, has remained unchanged since the 1970s.

“The continued burden of disease and newly available data relevant to early-onset GBS disease prevention from the fields of epidemiology, obstetrics, neonatology, microbiology, molecular biology, and pharmacology prompted revision of the guidelines for early-onset GBS disease prevention,” according to the CDC's report introducing the most recently revised guidelines (MMWR 2010;59[RR-10]:1–32).

A technical working group, which was formed to review and update the guidelines, identified a subset of topics for review, then revised the guidelines based on available evidence and expert opinion. Changes were made regarding both secondary prevention in newborns and maternal prophylaxis.

In large part, the revised guidelines are reaffirmation of the earlier guidelines, according to Dr. Carol Baker, professor of pediatrics, molecular virology, and microbiology at the Baylor College of Medicine, Houston, and a member of the technical working group charged with updating the guidelines.

“All women who are pregnant should be screened with cultures at 35–37 weeks. That's the main strategy to prevent early-onset disease in babies, and it hasn't changed one bit,” she said in an interview.

There was, however, some “tweaking” of the existing guidelines to simplify and clarify processes, add some new information about alternative laboratory methods for testing, and provide for alternative treatments – for example, for women allergic to penicillin, she said.

As for secondary prevention in neonates, a management algorithm for secondary GBS prevention, which is designed to detect potential cases as early as possible, remained mostly the same, except it was streamlined and now applies to all newborns.

Although the changes in the guidelines are generally small when it comes to secondary prevention in infants, they are important, and taken together, the changes for both mothers and babies are expected to provide some incremental improvements in outcome, Dr. Baker said.

The good news is there is 80% less early-onset GBS disease than there was before the culture screening recommendations came out in 1996, and that's real progress, she said, adding that there is room for improvement – particularly in late-onset disease, which hasn't changed much.

“We can probably do a little better with these [updated guidelines],” she said.

However, until the pharmaceutical industry moves forward with the available vaccine science and develops a GBS vaccine, it is doubtful much progress will be made in regard to late-onset disease, Dr. Baker said, noting that she believes the industry has failed to act on that science out of fear of the litigation so commonplace in obstetrics and maternal-fetal medicine.

Still, progress is being made, and good compliance with the guidelines is expected, particularly since the updated guidelines have been endorsed by the American Academy of Pediatrics, the American College of Obstetricians and Gynecologists, the American College of Nurse-Midwives, the American Academy of Family Physicians, and the American Society for Microbiology. All have had a hand in developing the guidelines, and thus have a stake in the outcomes, she noted.

“I'm very optimistic that there will be high compliance both on the baby side and the mother's side. It's a matter of education – hopefully the news will get out,” Dr. Baker said.

Indeed, the guidelines call for local and state public health agencies, in conjunction with hospitals, to establish surveillance for early-onset GBS, and to “take other steps to promote perinatal GBS disease prevention and education to reduce the incidence of early onset GBS disease in their states.”

The algorithm calls for a full diagnostic evaluation in all newborns with signs of sepsis, as well as provision of antibiotics active against GBS and other organisms that might cause sepsis pending the results of the evaluation. The evaluation should include “a blood culture; a CBC including white blood cell differential and platelet count; a chest radiograph if any abnormal respiratory signs are present; and a lumbar puncture if the newborn is stable enough to tolerate the procedure and sepsis is suspected,” according to the guidelines.

Also, well-appearing newborns whose mothers had suspected chorioamnionitis should undergo a limited evaluation (blood culture and CBC as above, but no chest x-ray or lumbar puncture is necessary) and should receive antibiotic treatment pending culture results. Well-appearing infants whose mothers had no chorioamnionitis and no indication for GBS prophylaxis should be managed according to routine clinical care.

Other key components of the algorithm call for the following:

▸ Observation for at least 48 hours – but no routine diagnostic testing – in well-appearing infants of any gestational age whose mother received adequate intrapartum GBS prophylaxis (clarified in the newly revised guidelines to be at least 4 hours of intravenous penicillin, ampicillin, or cefazolin before delivery). Observation now is also recommended in well-appearing infants born to mothers who had an indication for GBS prophylaxis but received no or inadequate prophylaxis, as long as the infant is at least 37 weeks' gestational age, and the duration of membrane rupture before delivery was less than 18 hours.

▸ Limited evaluation and observation for at least 48 hours in well-appearing infants born to mothers with an indication for prophylaxis, but who received no or inadequate prophylaxis, when the infant is less than 37 weeks' gestation or duration of membrane rupture before delivery was 18 hours or more.

Well-appearing infants with a gestational age of 35–36 weeks whose mothers received adequate intrapartum antibiotic prophylaxis do not routinely require diagnostic evaluations.

In addition to these steps, research aimed at better understanding the racial and ethnic differences that still persist in GBS disease incidence is needed, according to the CDC report. Research is needed on strategies for preventing early-onset disease among preterm infants, the role of bacteriuria as a risk factor, effectiveness of the recommended intrapartum antibiotic prophylaxis agents for penicillin-allergic women at high risk for anaphylaxis, the impact and effectiveness of recommendations for secondary prevention of early-onset disease among neonates, and factors contributing to the higher than anticipated proportion of early-onset GBS disease cases occurring among infants born to women with negative prenatal GBS screens. Such ongoing research is important because, in the absence of a licensed GBS vaccine, universal screening and intrapartum antibiotic prophylaxis continue to be the cornerstones of prevention, the report states.

“I'm very optimistic that there will be high compliance both on the baby side and the mother's side,” Dr. Carol Baker said.

Source Courtesy Marcia A. Rench