Group B Streptococcal Colonization in African Countries: Prevalence, Capsular Serotypes, and Molecular Sequence Types

Area of Science:

• Microbiology
• Epidemiology
• Vaccinology

Background:

• Group B Streptococcus (GBS) is a common bacterium in women, posing a significant risk for invasive neonatal infections globally.
• Intrapartum antibiotic prophylaxis is a key preventive measure, but its accessibility is limited in resource-constrained African settings, leading to a high disease burden.
• Serotype-based vaccines are under development as a viable alternative for preventing neonatal GBS infections.

Purpose of the Study:

• To review and summarize existing data on GBS serotype distribution and multi-locus sequence types (MLST) in various African countries.
• To provide essential epidemiological insights for assessing the efficacy of developing GBS vaccines.
• To identify GBS characteristics specific to Africa that may influence vaccine effectiveness.

Main Methods:

• Systematic review of published studies on GBS serotypes and MLST in Africa.
• Analysis of epidemiological data from different African regions.
• Comparison of African GBS data with findings from other continents.

Main Results:

• GBS serotype distribution and MLST profiles in Africa show similarities to other continents, with notable exceptions.
• Serotype V is the predominant GBS serotype among colonizing maternal strains across many African countries.
• Serotypes VI, VII, and IX, rare in Western nations, are prevalent in Ghana and Egypt, alongside unique African MLST sequence types.

Conclusions:

• A hexavalent GBS vaccine could offer extensive coverage for the African continent.
• Specific GBS serotypes and MLST types in Africa highlight the need for tailored vaccine strategies.
• Protein-based vaccines represent a promising alternative for GBS prevention in African populations.