From 2003 to 2006, cases of infection with group B streptococcus (GBS), which can be life threatening, have increased among black newborns in the US, new findings show. This occurred despite the release of guidelines in 2002 designed to prevent such infections.

GBS is the most common cause of sepsis (blood infection) and meningitis (infection of the fluid and lining surrounding the brain) in newborns and is a frequent cause of newborn pneumonia. Between 10 and 20 percent of infected infants die, and many of the survivors have permanent brain damage. The bacterium is passed from the mother to the baby during delivery.

For white infants, the rate of GBS infection in the first week of life (early onset) held steady at around 0.27 cases per 1000 live births from 2003 to 2006. For black infants, by contrast, the rate climbed from 0.53 to 0.86 cases per 1000 live births.

The revised guidelines, produced by the Centers for Disease Control and Prevention and other groups, called for all pregnant women to be tested for carriage of GBS at 35 to 37 weeks’ gestation, and for any women found to be carrying the bug to be given antibiotics during labor.

According to the analysis of data from a surveillance system, reported in the CDC’s Morbidity and Mortality Weekly Report, a total of 1199 cases of early-onset GBS disease and 1005 cases of late-onset disease were logged from 2000 to 2006.

The overall rate of early-onset disease dropped from 0.52 to 0.31 cases per 1000 live births from 2000 to 2003, researchers from the CDC and elsewhere report. However, from 2003 to 2006, the rate increased to 0.40 cases per 1000 live births, driven by the increasing rates seen in black infants.

Rates of late-onset disease generally held steady from 2000 to 2006, although there was a decrease in cases noted among black infants from 2005 to 2006.

The cause of the rise in early-onset GBS infection among black infants is unclear and “continued monitoring is needed to follow trends (in this group) to determine whether additional interventions are warranted,” the report emphasizes.

SOURCE: Morbidity and Mortality Weekly Report, February 13, 2009