Identification of Genital Colonization of Group B Streptococci Rate during Late Pregnancy and Its Correlates with Demographic Factors in Bundelkhand Region of Uttar Pradesh, India

Abstract

This study was undertaken to find the GBS colonization rate among women at > 28 weeks of gestation and to assess the type of specimens and techniques used for GBS detection and the demographic factors affecting the carriage in Bundelkhand region of Uttar Pradesh. A total of 434 consecutive vaginal and rectal swabs were obtained from 217 pregnant women at > 28 weeks of gestation and their follow-up testing. Swab specimens were compared on Islam and Edwards blood agar plates, and into selective Lim broth. Enrichment Lim cultures (< 12 h) with and without positive modified coagglutination test were then cultured on Edwards sheep blood agar plates. GBS was isolated from at least one of the specimen from the patients in 66 cases with an overall colonization rate of 30.4%. Of the 56 new-borns, there were 18.2% (12/56) mothers GBS positive and of these 6 (50%) new-borns were found to be GBS positive. Direct specimen culture one (E)dwards blood agar and Islam agar medium revealed 85% sensitivity and 100% specificity with 94% accuracy respectively. The 2nd technique revealed high sensitivity of 100, 90.6 specificity and 94 respectively. The percentage of GBS isolated from high-level swabs, low-vaginal swabs and rectal swabs were almost similar among the primary specimens. Group B streptococci rate among pregnant women is relatively high and thereby constitutes a group of women whose infants are at great risk of early onset of invasive disease.

Keywords: Group B Streptococci, maternal colonization, neonatal transmission, prenatal screening