Prevalence of Group B Streptococcus colonisation and associated risk factors among women delivering at Kawempe Hospital, Uganda

Abstract

Background: Colonization with Group B streptococcus (GBS) bacteria is common among women of reproductive age, and at least one in every four expectant mothers is GBS colonized. While GBS colonization may not present any serious dangers to the woman, it may be associated with life threatening infections when passed on to the new-born including, meningitis and sepsis. There is no regular screening for GBS in the current Ugandan health policy for expectant women making it hard to establish its burden and design prevention interventions for the pregnant women and their babies. Objectives: To identify the prevalence and risk factors of group B streptococcus (GBS) colonization among women delivering at Kawempe National Referral Hospital (KNRH) and explore feasibility of GBS screening in pregnancy. Methods: An unmatched case-control study was conducted to study prevalence and factors associated with GBS colonization among 203 cases and 203 controls. Cases were mothers who had a positive microbiological culture of GBS result while the controls were mothers who had a negative microbiological culture of GBS from rectovaginal swabs. A logistic regression model was fitted to analyse risk factors for maternal GBS colonisation. Fifteen key informant interviews were also conducted to explore the feasibility of conducting routine GBS screening in pregnancy. Results: The GBS colonization rate was observed as 14.77%. Rupture of membranes greater than 18 hours before delivery increased odds of GBS colonization by more than double (OR= 2.45 95% CI 0.63-9.61). Multigravida (p=0.050, OR=0.65: 95% CI: 0.42-1.00) at bivariate analysis was found to be protective against GBS colonization but there was no statistically significant association at multivariable analysis (p=0.090, OR=0.46 95% CI 0.19-1.13). From the qualitative component of the study, there was a lack of knowledge and information on GBS infection and screening among the midwives and nurses. Hospitals would need to prepare in terms of space, staffing and equipment if the screening program were to be implemented. Conclusions: Study findings show that the prevalence of GBS colonization among pregnant women is low but comparable to previous studies and there were no factors specifically associated with GBS colonisation. Knowledge on GBS among both the health workers and the community is also low indicating a need to increase awareness among both the patients and x providers but to also progressively prepare facilities to initiate GBS screening programs to limit risks of transmission to unborn babies