Group B streptococcus in pregnant women and neonates in Africa: a scoping review

Group B streptococcus (GBS) affects approximately 19.7 million pregnant women, causing about 58 300 (0.3%) infant deaths globally, with highest disease burden observed in Africa. Providing a Kenyan advisory board with evidence guiding maternal GBS priority interventions, we reviewed evidence and identified gaps on determining factors, vertical transmission rates (VTR), signs and symptoms, provision of care, burden, testing, comorbidities, sequelae, and management of maternal GBS colonisation and neonatal early-onset disease (EoD) in Africa.

We searched MEDLINE, EMBASE, Web of Science and Global Index Medicus, CINAHL and SCOPUS, CENTRAL, ClinicalTrials.gov and WHO Trials Register and MedRxiv. Two independent reviewers screened studies and extraction was conducted independently. We did not assess risk of bias or methodological rigour. Results were presented descriptively.

Our search yielded 835 studies; we included 59. Most studies were cross-sectional (n=41, 69.5%). Studies were mainly from Eastern (n=29), Southern (n=15) and Western Africa (n=14). Participants totalled 31 544 women and 8244 neonates. Most studies (n=46, 77.9%) focused on maternal GBS colonisation, highlighting a myriad of determining factors like age below 25 years (OR 2.07). VTR ranged between 33.0% and 59.1%. Signs and symptoms included dyspareunia in pregnancy (23.3% of 279 women) and respiratory distress (OR 0.11) among neonates. Rectovaginal and/or vaginal colonisation and EoD prevalence among all neonates ranged from 1.8%-64.0% in pregnancy and 6.8%-65.1% in neonates. Nearly all studies (n=58) reported on testing criteria, mainly culture methods both in pregnancy (n=45 studies) and neonates (n=25 studies). HIV/AIDS was the most common comorbidity in women (OR range: 2.8 to 4.22). Meningitis was a common sequela in four studies, one reporting presence in 36.4% of participants. Ampicillin was the most common antibiotic reported in three studies. No evidence of maternal mortality was found.

Most evidence concerns maternal colonisation, mainly testing and prevalence. Most research is from the Eastern, Southern and Western regions, with limited evidence from the Central and Northern regions. Main gaps are in EoD burden, maternal mortality, sequelae, comorbidity and management. Testing/reporting of GBS should be adapted. Systematic reviews on determinant factors and the effectiveness of management strategies will better inform the prioritisation of GBS interventions.