ICPs urged to take lead in protecting newborns

CDC asks them to spearhead prevention

In an unusual direct appeal to infection control professionals, public health officials are asking ICPs to champion hospital efforts to prevent a leading cause of illness and death in newborns — group B streptococcal (GBS) disease.

"We wanted to get the word out that there is a lot that [ICPs] can do that some of them may not be aware of," says Stephanie J. Schrag, DPhil, an epidemiologist in the respiratory infections program at the Centers for Disease Control and Prevention. "Some [ICPs] may feel like group B strep prevention is not something that they can have an impact on."

Despite recent declines, early onset GBS is still a leading cause of neonatal sepsis in the United States, resulting in about 2,200 infections each year among children less than a week old.¹ There are proven interventions to prevent perinatal transmission of GBS from mother to newborn, but CDC data indicate as many as 40% of hospitals do not have an official GBS prevention policy, Schrag says. Yet even with only partial compliance, increasing emphasis on prevention resulted in a 65% decline in GBS from 1993-1998. With group B strep on the run as a neonatal nemesis, officials are appealing to ICPs to step up efforts.

"We have interventions that are effective," Schrag tells Hospital Infection Control. "We have really seen substantial declines following the development of guidelines for prevention and implementation. There is really something people can do to prevent this bad disease. In places where that isn’t happening, it is an exciting time to implement a policy because there is evidence that it will make a difference."

After GBS emerged as the leading infectious cause of infant mortality in the 1970s, clinical trials began that eventually revealed administering antibiotic prophylaxis during labor could prevent disease in the newborn. Some 20% of pregnant women are colonized with GBS at the time of labor and thus have the risk of transmitting the bacteria to their newborns. However, the health care system has been slow to implement the measures, despite 1996 consensus guidance by the CDC and other medical groups.

"We have shown in previous studies that having a policy can be associated with declines in the incidence of disease," Schrag says. "And [ICPs] have played roles in getting policies established. If they are in an institution that currently doesn’t have a policy, they can coordinate and spearhead the movement to get one. If a place already has a policy, there is work they can do in evaluating the policies. They can also play an important role in monitoring the implementation and impact of the policy. I think that is a piece that is not being done so commonly."

Group B strep infection is more often viewed as a perinatal infection than a classic nosocomial event, but it happens in the hospital, and that is where prevention must occur, she says. To emphasize that need, Schrag and colleagues recently published an overview of the situation that calls upon ICPs and hospital epidemiologists to spearhead GBS prevention programs.² ICPs can be the point-people in a prevention effort that cuts across several specialties. "One of the tricks in group B strep prevention is that there are so many different players involved — obstetricians, pediatricians, gynecologists, nurses, and midwives," she says. "Having one person who may work with a lot of different groups is important."

In addition to tracking GBS cases in the hospital, ICPs can collect information on the number of live births annually at the hospital and the basic demographics of the population of pregnant women the hospital serves, the CDC advises. In terms of administering antibiotics, identifying women as candidates for prophylaxis can be done by two alternative methods.

One is to administer drugs based on risk factors (e.g., fever, prolonged rupture of membranes, premature delivery). The other approach is to screen all pregnant women for GBS between 35 and 37 weeks gestation and identify carriers for prophylaxis. Factors such as lab capabilities and prenatal care of the patient population should be considered in selecting an approach, Schrag says.

Despite the strides made against GBS, there is room for considerable improvement in the delivery of antibiotic prophylaxis to women at risk. In CDC sentinel data from 1998 and 1999, only 21% of mothers of infants with GBS had received intrapartum antibiotic prophylaxis.³ (See table, p. 134.) "Definitely, the majority did not receive antibiotics," Schrag says. "We feel like there is room to improve implementation."

In addition, prenatal screening often was not performed at the recommended time, and combined vaginal and rectal swabs were rarely documented. Approximately 70% of women who were unscreened and developed a risk factor did not receive intrapartum antibiotics. Many women were unscreened and did not present with risk factors at the time of labor, the CDC noted. That suggests that some early onset disease may have been prevented if the screening-based approach (vs. the risk-based approach) had been used. Other women did not receive antibiotics until after they developed fever, suggesting that cases might have been prevented if antibiotics could have been administered earlier in the hospital admission (e.g., one dose of penicillin or ampicillin at least four hours before delivery).

Intravenous ampicillin, clindamycin, and penicillin are the most commonly administered antibiotics, but there is growing concern about antibiotic resistance issues. In CDC data on GBS isolates from 164 patients, 32 (20%) isolates were resistant to erythromycin, and 25 (15%) were resistant to clindamycin. All isolates were susceptible to penicillin.

While penicillin resistance among GBS isolates has not been reported, erythromycin and clindamycin resistance may be increasing. For women with a history of severe penicillin allergy, clinicians should request that prenatal GBS screening include susceptibility testing of GBS isolates to determine an appropriate regimen for intrapartum prophylaxis. Cefazolin should be considered when erythromycin or clindamycin resistance occurs among women with penicillin allergy.

"At this stage, we certainly don’t have any evidence that people should be so concerned that they wouldn’t implement the [prevention] policy," Schrag says, "especially now that we have shown that it can have such a big impact. But antibiotic resistance is something we do want to monitor as group B strep prevention becomes more widespread. We have monitoring in place already in our surveillance areas."

(Editor’s note: CDC articles, guidance, and recommendations for GBS are available on the CDC’s Web site at http://www.cdc.gov/ncidod/dbmd/gbs/index.htm.)

References

1. Schrag SJ, Whitney CG, Schuchat A, et al. Neonatal group B streptococcal disease: How infection control teams can contribute to prevention efforts. Infect Control Hosp Epidemiol 2000; 21:473-483.

2. Schrag SJ, Zywicki S, Farley MM, et al. Group B streptococcal disease in the era of intrapartum antibiotic prophylaxis. N Engl J Med 2000; 342:15-20.

3. Centers for Disease Control and Prevention. Early-onset group B streptococcal disease — United States, 1998-1999. MMWR 2000; 49:793-796.