Methods: Lower vaginal and rectal swabs were collected from third trimester pregnant women at Dr. Ram Manohar Lohia Hospital, a tertiary center serving a diverse population in the Central District of Delhi. Swabs were placed in Strep B Carrot Broth™ selective chromogenic media and subculture was performed on GBS Detect™ plates. GBS was confirmed using StrepPRO™ grouping reagent. Isolates were serotyped using ImmuLexTM Strep-B latex kits (Statens Serum Institute, Denmark) containing antisera to GBS capsular polysaccharides (CPS) Ia, Ib and II-IX. Demographic and clinical data were collected.
Results: From August 2015 to April 2016, 300 pregnant women (mean age 26.9 [range 19-29] years; mean gestation 34 [range 28-42] weeks) were enrolled. GBS colonization prevalence was 15%. Of these women, 15% had vaginal, 29% had rectal and 56% had colonization at both sites. CPS types were III (22.2%), V (20%), II (20%), Ia (13.3%), VII (6.7%) and Ib (4.4%); 13.3% were nontypable. Rural vs. urban dwelling, crowding, and educational level did not differ in colonized vs. non-colonized women. 20.7% had a history of spontaneous abortion; fetal loss at ≥20 weeks’ gestation was significantly more common in GBS colonized than non-colonized women (15.6% vs. 3.5%; p=0.004). Employing Census of India 2011 data for the annual birth cohort (24.9 million) and estimating that 1% of neonates born to GBS colonized women will develop early-onset disease, at least 18,697 cases of early-onset GBS disease occur yearly in India.
Conclusion: Using optimal methods, 15% of third trimester pregnant women in India are GBS colonized. We provide the first contemporary data regarding GBS serotypes in an Indian population. A multivalent vaccine containing 6 CPS types (Ia, Ib, II, III, V and VII) would encompass ~87% of GBS carried by pregnant women in India.
Thrasher Research Fund, Early Career Award:
P. Singh, None
C. Hans, None
C. J. Baker, Pfizer, Inc.: Consultant , Consulting fee
CureVac, Inc.: Consultant , Consulting fee
Seqirus, Inc.: Consultant , Consulting fee
M. Edwards, None