Jan. 5, 2000 (Los Angeles) -- Giving penicillin to some women in labor can dramatically decrease the incidence of a serious, often fatal infection in their newborns, according to a new study published in TheNew England Journal of Medicine. The finding is "a public health success story," lead author Stephanie Schrag, PhD, tells WebMD.
Group B streptococcal infection was the leading cause of illness and death in infants in the U.S. and other countries as recently as the 1970s, says Schrag. "However, it was a problem where something could actually be done, because the prevention strategy was known." That strategy was to administer penicillin during the intrapartum period, referring to when the woman is in labor.
By the 1990s, a concerted effort was under way to provide penicillin to any woman identified as having a high risk of passing the infection to her infant, and in 1996 consensus guidelines were issued by the American Academy of Pediatrics, the American College of Obstetricians and Gynecologists, and the CDC. By the end of the decade, says Schrag, who is with the CDC, "we were in a position to examine the effect of the prevention strategy."
She and her colleagues analyzed data from a program of active surveillance for group B streptococcal disease to determine how prevention efforts affected the incidence of the disease from 1993 to 1998. The surveillance system identified all cases occurring in a population ranging from 12 million (in 1993) to more than 20 million (in 1998).
During the five years of the study, the surveillance system identified over 7,800 cases of invasive group B streptococcal disease. Between 1990 and 1993, the incidence of early-onset disease, defined as disease occurring in infants less than seven days old, remained fairly constant, but it began to drop in 1993 and was associated with a particularly sharp decrease following the release of the consensus guidelines in 1996. Overall, it declined by 65% between 1993 and 1998, from 1.7 per 1,000 live births to 0.6 per 1,000 live births.
This strategy prevents early-onset disease but not the late-onset form, defined as that occurring in babies seven to 89 days old, Schrag explains. Early-onset disease may cause meningitis or pneumonia and is often fatal. Infants who survive may be mentally retarded or have hearing or vision problems. Babies get the early-onset infection from their mothers, while they probably contract the late-onset version from someone else. The symptoms of late-onset infection include pneumonia, meningitis, and the presence of bacteria in the blood. Schrag and her colleagues are studying how the late-onset disease is transmitted and the best ways to prevent it.
Approximately one in every four women carries group B streptococci as part of the normal vaginal and gastrointestinal environment and have no symptoms from it, Schrag tells WebMD. Patients who test positive for the bacterium late in pregnancy are at high risk of passing the infection to their infants and should be offered the antibiotics during labor. Other risk factors include running a fever during labor, membrane rupture that persists longer than 18 hours, and premature delivery. According to Schrag, all of these patients should receive intrapartum penicillin or, if they are allergic to penicillin, a second-line antibiotic.
"The good news is, there's a strategy to prevent this infection in newborns," she says. She urges pregnant women to discuss their risks with their doctors and to ask about prevention policies at the hospital in which they will deliver.
- Approximately one in four women carry group B streptococci as part of their normal vaginal and gastrointestinal environment, but experience no symptoms.
- These women are at high risk of passing the infection to their children during childbirth and should be given a preventive dose of penicillin during labor.
- Programs to administer penicillin to women at high risk of passing group B strep to their infant has reduced the incidence of infection in newborns by 65%.