A systematic review and meta-analysis of the bacterial profile of ready-to-eat vegetable salads across Africa.

BACKGROUND

Ready-to-eat vegetable salads are increasingly consumed across Africa due to their convenience and perceived health benefits. However, these foods are often prepared without terminal heat treatment, making them potential vehicles for foodborne pathogens. Evidence of the burden and distribution of bacterial contamination in ready-to-eat vegetable salads across Africa remains fragmented. Therefore, this study aimed to perform a systematic review and meta-analysis of the prevalence of bacterial pathogens isolated from ready-to-eat vegetable salads across Africa.

METHODS

We searched PubMed, Scopus, and Google Scholar on 25 September 2025. Guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) guidelines, eligible African studies reporting bacterial isolation from ready-to-eat vegetable salads were analyzed using random-effects models. Heterogeneity, publication bias, and single study influence on pooled prevalence were assessed. While this review was not prospectively registered in PROSPERO, we searched the registry to confirm no similar reviews existed and adhered strictly to PRISMA reporting standards.

RESULTS

Thirty-one (n = 31) studies were included. Gram-negative bacteria predominated among reported isolates. Meta-analysis was restricted to bacterial species reported in at least five studies to ensure stability of pooled estimates. Escherichia coli (40%; 95% CI: 20-64%) and Salmonella spp. (32%; 95% CI: 16-54%) were the most frequently reported organisms. Among Gram-positive bacteria, Bacillus cereus (28%; 95% CI: 14-48%) and Staphylococcus spp. (26%; 95% CI: 13-47%) were commonly identified.

CONCLUSION

Ready-to-eat vegetable salads across Africa are frequently contaminated with bacterial communities, including both pathogenic and non-pathogenic organisms. This finding highlights the need for strengthened food safety practices and routine microbiological surveillance.