GBS screening, treatment raise sepsis concerns: CDC now favors universal screening-based approach over risk-based method. (Shift in Pathogens).

BANFF, ALTA. -- Amid recent concerns about a rise in sepsis caused by ampicillin-resistant Escherichia coli in very-low-birth-weight neonates, experts are wondering whether new guidelines on group B streptococcal infection in pregnancy might contribute to a shift in the pathogens causing sepsis among neonates in general.

"We have seen a sea change in the epidemiology of neonatal sepsis," Peter H. Gilligan, Ph.D., commented at the annual meeting of the Infectious Diseases Society for Obstetrics and Gynecology.

Dr. Gilligan, director of clinical microbiology-immunology laboratories and phlebotomy services at the University of North Carolina Hospitals, Chapel Hill, pointed to a recent study showing alarming increases in the rates of neonatal sepsis due to ampicillin-resistant F. coli in very-low-birth-weight infants.

In the study, researchers at Emory University, Atlanta, investigated neonatal sepsis rates among 13,053 such infants born between 1991 and 2000. While early-onset group B streptococcal (GBS) sepsis declined dramatically from 5.9 to 1.7 cases/1,000 live births, sepsis caused by E. coli increased from 3.2 to 6.8 cases per 1,000 live births.

Moreover, most of the E. coli isolates were resistant to ampicillin. Mothers of infants with ampicillin-resistant E. coli infections were more likely to have received intrapartum ampicillin than those with ampicillin-sensitive strains (N. Engi. J. Med. 347[43:240-47, 2002).

While the indications for antibiotic usage in the study are unknown, one possibility is that resistant isolates may have arisen as a result of mothers receiving ampicillin prophylactically under the Centers for Disease Control and Prevention's 1996 guidelines for screening and treating GBS in pregnancy

There's no question that by following the GBS guidelines "we are increasing antibiotic use," said Stephanie Schrag, Ph.D., of the CDC, Atlanta, which released an updated version of the GBS screening and treatment guidelines last month. The new guidelines favor a universal screening-based approach over the risk-based method (MMWR 51[RR-8]:1-52, 2002).