Objectives: To assess the prevalence of maternal and neonatal group B Streptococcal colonization, incidence of neonatal systemic illness, and antibiotic sensitivity of isolates.

Methods: This prospective cohort study was conducted in a South Indian tertiary care hospital. Rectovaginal swabs from pregnant mothers at 360/7-376/7 wk gestation and throat and rectal swabs from their neonates at 48 h of age were collected. Presence of group B Streptococcus (GBS) was identified by broth enrichment step, and traditional microbiologic methods and antibiotic sensitivity of isolates was noted. All mothers received intrapartum antibiotic prophylaxis (IAP). Culture-positive sepsis, clinical sepsis, pneumonia, meningitis, and urinary tract infection were defined as neonatal systemic illness. Neonates of colonized mothers were followed at 3 mo for late-onset sepsis.

Results: Of the 310 mothers, 40 were GBS colonized (prevalence: 12.9%; 95% CI 9.2%, 17.6%). None of the neonates were colonized. Maternal GBS colonization was significantly associated with premature rupture of membrane (RR - 2.93, 95% CI - 1.66-5.16) and neonatal systemic illness (RR - 2.78, 95% CI - 1.39-5.54). Positive correlation was noted between duration of IAP ≤ 4 h and neonatal illness and between maternal GBS colonization and Apgar at 1 min ≤ 4. Clindamycin resistance was noted in 20%. All neonates remained well at 3 mo follow-up.

Conclusion: High maternal colonization alerts the need for GBS screening in India. Clindamycin resistance among GBS isolates questions its effectiveness as alternative therapy in penicillin allergy.