ABSTRACT
EPIDEMIOLOGY/INCIDENCE (FIG. 37.1) GBS is a major cause of infectious morbidity among infants. In the United States, it is the most common cause of serious bacterial sepsis, including neonatal meningitis. The prevalence of asymptomatic GBS anovaginal colonization in pregnant women is about 20%, with a range of 10% to 30% (1). GBS colonization during pregnancy can be transient or persistent. A substantial portion of women who are colonized during one pregnancy will not have GBS colonization during a subsequent pregnancy. Usually 40% to 75% of neonates born to colonized mothers are colonized themselves (2). As a result of prevention efforts employing screening and antibiotic prophylaxis, the incidence of early-onset GBS sepsis fell in United States from 1.7 cases per 1000 live births in 1990 to 0.34 to 0.37 per 1000 live births in 2004 through 2008 (1).
