Selective intrapartum chemoprophylaxis of neonatal group B streptococcal early-onset disease. III. Interruption of mother-to-infant transmission.

The effect of intrapartum ampicillin treatment on vertical transmission of group B streptococci (GBS) was examined in 575 prenatally colonized parturient women and their 580 newborn infants. Eighty women (43 receiving ampicillin) with premature labor and/or prolonged rupture of amniotic membranes were randomized. The other 495 were stratified into groups of 358 (31 receiving ampicillin) with no perinatal risk factors; 119 (28 receiving ampicillin) with premature labor and/or prolonged membrane rupture; and 23 (18 receiving ampicillin) with intrapartum fever.

Selective intrapartum chemoprophylaxis of neonatal group B streptococcal early-onset disease. II. Predictive value of prenatal cultures.

To determine the value of prenatal cultures in defining maternal colonization status at delivery, 5,586 pregnant women were screened at prenatal visits for vaginal and rectal carriage of group B streptococci (GBS). GBS were isolated from 1,272 (22.8%).

Selective intrapartum chemoprophylaxis of neonatal group B streptococcal early-onset disease. I. Epidemiologic rationale.

Between 1973 and 1981, 61 cases of neonatal group B streptococcal early-onset disease occurred among 32,384 infants born at Michael Reese Hospital and Medical Center, Chicago. Forty-one (67%) of the 61 affected infants were bacteremic at birth, implying intrapartum acquisition of infection. No significant deviations from the overall attack rate of 1.

Rapid identification of material colonization with group B streptococci by use of fluorescent antibody.

To identify women colonized with group B streptococci during parturition, we used pooled type-specific fluorescent antibody to examine vaginal swabs enriched by preincubation in selective broth medium. In preliminary experiments, group B streptococcus strain III-Bell was reliably detectable with fluorescent antibody at concentrations of greater than 10(5) colony-forming units per ml, achieved after 6 h of incubation of small inocula (18 to 26 colony-forming units). Of the vaginal swabs from 924 parturient women examined prospectively by both fluorescent antibody and selective bacteriology techniques, group B streptococci were isolated in 154.