# Prevalence of Group B Streptococcus Colonization and Invasive Infection in Nigeria: A Systematic Review and Meta-Analysis

## TL;DR

This study summarizes the prevalence of Group B Streptococcus in Nigeria, showing regional differences and the need for better surveillance and prevention.

## Contribution

The first systematic review and meta-analysis on GBS colonization and invasive disease in Nigeria.

## Key findings

- The pooled GBS colonization rate in Nigeria is 12.0%, with higher rates in Southern Nigeria.
- Neonates have a 16.0% colonization rate, and invasive GBS disease occurs only in neonates at 3.0%.
- Serotypes V and II and ST19, ST182, and ST28 are the most common in Nigeria.

## Abstract

Objective: This study provides the first systematic synthesis of the burden of Group B Streptococcus (GBS) colonization and invasive disease in Nigeria, with emphasis on prevalence, serotypes, and sequence types (STs). Method: This systematic review and meta-analysis were conducted in accordance with the PRISMA guidelines and was registered on PROSPERO (CRD420251155310). Searches were conducted across multiple databases, including Scopus, ScienceDirect, Web of Science, PubMed, Dimensions, and African Journals Online, as well as in Google Scholar and Google to identify relevant articles. In total, 426 records were retrieved, of which 43 studies met the inclusion criteria. A random-effects model was applied to estimate the pooled prevalence. Result: The pooled prevalence of GBS colonization in Nigeria was 12.0% (95% CI: 9.0–15.0%). Higher colonization rates were observed in Southern Nigeria (13.0%) than in Northern Nigeria (9.0%). The neonatal colonization rate was 16.0%. Colonization rates were 13.0% in pregnant women and 8.0% in non-pregnant individuals. Human immunodeficiency virus status showed no significant association with GBS colonization among pregnant women (OR = 1.47, p = 0.17). Invasive GBS disease was uncommon (3.0%) and occurred only in neonates. Across included studies, serotypes V and II were the most frequently reported, with ST19, ST182, and ST28 being the predominant STs. Conclusions: GBS colonization is common in Nigeria, with marked regional variation and heightened neonatal vulnerability to invasive GBS infections. Notably, nineteen states lacked surveillance data, highlighting substantial gaps in national monitoring. These findings highlight the importance of strengthening prevention strategies, expanding surveillance coverage, and implementing maternal screening and immunization programs to mitigate the burden of GBS.