Meta-analysis finds 9% Shigella prevalence across human, animal, food, and environmental samples in Cameroon

BACKGROUND: Shigellosis, a major cause of diarrhoea in low- and middle-income countries, presents a significant public health challenge due to its high morbidity and mortality, particularly among children under five. The local epidemiology and resistance patterns of Shigella species in Cameroon remain poorly characterised. This systematic review and meta-analysis aims to determine the prevalence and antibiotic resistance patterns of Shigella species in Cameroon. METHODS: This systematic review and meta-analysis adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement and was registered with the International Prospective Register of Systematic Reviews (PROSPERO). A comprehensive search of databases was performed up to June 2025 to identify observational studies reporting Shigella prevalence. Data were extracted using a pre-tested standardised form, and the risk of bias was assessed with the Hoy et al. checklist. Meta-analyses were performed using a DerSimonian-Laird random-effects model in R software to estimate the pooled prevalence of Shigella. Heterogeneity was assessed using Cochran's Q test and the I statistic. RESULTS: A total of 23 studies were included, surrounding 24,847 total units of analysis (including humans, animals, food and environmental samples). The overall pooled prevalence across all sources was 9% (95% CI, 5.51%-14.76%; I = 93.3%). When restricted to human patient populations (n = 24,464 individuals), the pooled prevalence was 6% (95% CI, 3%-12%; I = 94.0%). Prevalence rates in non-human sources were 6% in animals (n = 358), 9% in food samples (n = 1371) and 6% in environmental samples (n = 610). Among identified species, S. flexneri was most common (36.4%). CONCLUSION: Our findings indicate a significant burden of shigellosis in Cameroon, coupled with a concerning level of resistance to first-line antibiotics. This high prevalence of antimicrobial resistance (AMR) suggests that current empirical treatments may be ineffective, underscoring the critical need for a continuous surveillance program to guide clinical and public health interventions.