Although now less frequent because of preventive antibiotics, meningitis caused by group B streptococcal (GBS) bacteria is still a serious illness causing a high rate of death and severe complications in infants, reports a study in the November issue of the Pediatric Infectious Disease Journal.
"Despite advances in intensive care, 26 percent of term and near-term infants with GBS meningitis die or have neurologic impairment at hospital discharge," concludes the study by Dr. Fatma Levent and colleagues of Baylor College of Medicine and Texas Children's Hospital, Houston.
A review of hospital records from 1998 to 2006 identified 53 full-term infants with GBS meningitis. The disease was considered "early onset" in six infants who became ill during the first week after birth, and "late onset" in 47 infants who became ill after the first week.
Meningitis caused by GBS was once a fairly common disease of newborns, often transmitted at birth from mothers who are colonized by the GBS bacteria. Beginning in the 1990s, hospitals started giving preventive antibiotics during the last weeks of pregnancy (intrapartum antibiotic prophylaxis) to mothers colonized with GBS.
Follow-up data on the 53 infants showed that GBS meningitis is still a very serious infection. Three of the infants died, and another eleven were left with neurological impairment (such as seizures or muscle spasticity). Thus more than one-fourth of infants with GBS meningitis died or had severe complications. The risk was higher for infants with early-onset versus late-onset GBS meningitis: 50 versus 17 percent.
Certain factors were associated with an increased risk of such adverse outcomes. Infants who were having seizures by the time they were admitted to the hospital were at particularly high risk of death or neurological impairment.
With the introduction of intrapartum antibiotic prophylaxis, the rate of early-onset GBS meningitis has declined sharplyby at least 80 percent from 1993 to 2008, according to one study. Preventive antibiotics don't affect the risk of late-onset GBS meningitis, which has actually become slightly more common.
"Despite a decline in early-onset infant GBS disease in recent years, the diagnosis of GBS meningitis...continues to carry a high risk for an adverse outcome," the researchers write. They suspect that the true impact of the disease is even greater, as some infants who survive with apparently normal neurological function may experience subtle developmental delays or learning disabilities later in childhood.
Levent and colleagues call for further studies to assess the long-term outcomes of infants with GBS meningitis. "Even more importantly," they write, "methods to prevent these infections should be a public health priority."