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