Group B streptococcus colonization and HIV in pregnancy: A cohort study in Nigeria

BACKGROUND: Group B streptococcus (GBS) is a leading cause of maternal and neonatal infectious morbidity. HIV is prevalent among pregnant women in Nigeria. AIM: To determine the rates of anogenital GBS colonization in our institution and compare GBS colonization rates between HIV positive and negative pregnant women. METHODS: A cross-sectional comparative study was conducted over 6 months. Patients were separated according to their HIV status: positive and negative. GBS colonization was assessed by vaginal and anal swabs collected at 35–37 weeks of gestation and cultured in Todd-Hewitt broth, followed by a confirmatory test. Socio-demographic characteristics and CD4 count were extracted from patient medical records. Secondary outcomes were identification of risk factors for GBS colonization, antibiotic sensitivity, and any association between CD4 count and GBS colonization. Appropriate statistical analysis was done. RESULTS: A total of 200 patients attended the clinic; 67 HIV positive and 133 negative. Analyzed samples were 198; the overall prevalence of GBS was 18.2%. No significant difference in GBS colonization was noted between HIV positive (19.4% [ 13 ]) and negative patients (17.6% [ 23/131 ]). Most GBS isolates were susceptible to ampicillin (87%) and penicillin (81%). A high body mass index (BMI) was independently associated with GBS colonization (OR = 1.25, 95% CI: 1.04–1.51). No association was observed between CD4 counts and GBS colonization. CONCLUSION: A high prevalence of GBS colonization was observed in our institution. Colonization rates were independent of the HIV status but associated with a high BMI in HIV positive women.