Prevalence of Streptococcus agalactiae Serotypes Associated with Anogenital Colonization among Pregnant Women in Jos

Aim: The aim of this study was to determine the prevalence of GBS serotype distribution in Jos University Teaching Hospital.

Materials and Methodology: This was a hospital based descriptive cross-sectional study of 300 women receiving health care at the Jos University Teaching Hospital between July 2017 and November 2017. Systematic sampling technique was employed in recruiting consenting subjects for this study. High vaginal and anorectal swabs were collected from each subject after obtaining their consent by signing a structured consent form. The identified Streptococcus agalactiae (GBS) isolates were serotyped using immuLex strep-B antisera from SSI Diagnostica, 2 Herredysvejen, DK-3400 Hillerod Demnark to identify the different serotypes. The results obtained were computed using SPSS version 21.

Results: A total of 300 women obtaining health care in Jos University Teaching Hospital (JUTH) were enrolled in this study between the months of July, 2017 and November, 2017. In all, vaginal and anorectal swabs were taken from 200 pregnant women and 100 non-pregnant women. The age range of the study population was between 16 years to 48 years with a mean age of 31.9 year (SD ± 6.6). The prevalence rate among the study population was 6.3%. The colonization rate among pregnant and non-pregnant women was 6.5% and 6.0% respectively with no significant statistical difference. Serotype Ia was the commonest isolate responsible for 42.1% of the GBS isolates. Serotype III accounted for 31.6% of the isolates, followed by serotype V (15.8%). Serotype II was less common, responsible for only 10.5%.

Conclusion: This study showed that GBS colonization rate among the study population was 6.3%. Approximately, 6.5% and 6.0% prevalence rate were found among pregnant and non-pregnant women respectively. Of all the GBS isolates, serotypes Ia, II, III, and serotype V were isolated with serotype Ia being the most prevalent serotype. This knowledge of serotype distribution will help in instituting serotype specific GBS vaccines for the prevention of GBS diseases in Jos.