Group B Streptococci Colonization in Pregnant Guatemalan Women: Prevalence, Risk Factors, and Vaginal Microbiome

BACKGROUND Infection causes 1 of every 5 neonatal deaths globally. Group B Streptococcus (GBS) is the most significant pathogen, although little is known about its epidemiology and risk in low-income countries. METHODS A cross-sectional study in 2015 at a public hospital in Guatemala City enrolled women ≥35 weeks' gestation. Vaginal and rectal swabs were processed using Lim broth and GBS CHROMagar then agglutination testing. Risk factors were assessed using multivariate analysis. Vaginal microbiota were profiled by 16S ribosomal ribonucleic acid sequencing in a subset of 94 women. RESULTS Of 896 pregnant women, 155 (17.3%; 95% confidence interval [CI], 14.9-19.9) were GBS colonized. Colonization was associated with history of previous infant with poor outcome (odds ratio [OR], 1.94; 95% CI, 1.15-3.27) and increasing maternal age (OR, 1.05; 95% CI, 1.02-1.09). Multiparity was protective (OR, .39; 95% CI, .21-.72). Four (6%) GBS-exposed infants had early-onset neonatal sepsis. Vaginal microbiome composition was associated with previous antibiotic exposure (P = .003) and previous low birth weight infant (P = .03), but not GBS colonization (P = .72). Several individual taxa differed in abundance between colonized and noncolonized women. CONCLUSIONS Group B Streptococcus is prevalent in pregnant women from Guatemala with different risk factors than previously described. Although the vaginal microbiome was not altered significantly in GBS-colonized women, use of antibiotics had an effect on its composition.