Prevalence of Rift valley fever in Eastern Africa: A systematic review and meta-analysis in humans and animals

Background Rift Valley fever (RVF) is a mosquito-borne, climate-sensitive zoonosis with major public health and veterinary impact in Africa and the Arabian Peninsula. Despite recurring outbreaks, RVF virus (RVFV) prevalence in humans and animals remains poorly defined. We conducted a systematic review and meta-analysis using a One Health approach to quantify RVFV prevalence and identify geographic and diagnostic patterns in Eastern Africa. Methods We searched PubMed, Scopus, and Web of Science for studies published between January 1, 2014, and December 31, 2024, reporting RVFV prevalence in humans, cattle, and small ruminants across 15 Eastern African countries. Risk of bias was assessed using the Joanna Briggs Institute checklist. Pooled prevalence was estimated using random-effects models, with subgroup analyses by country and symptom status. Publication bias was evaluated via Egger’s test and the trim-and-fill method. Results Seventy-eight studies involving ~ 76,000 individuals met inclusion criteria. Past RVFV infection prevalence was highest in cattle (15·31%), followed by small ruminants (8·92%) and humans (8·82%). Heterogeneity was high (I² > 90%), and publication bias was evident in animal studies. Geographic differences likely reflect variations in surveillance and diagnostics. RVF is widespread yet under-recognized, highlighting the need for integrated, climate-aware One Health surveillance and coordinated regional control strategies. Conclusion Although RVF remains under-recognized, it is widely endemic in Eastern Africa. Its high seroprevalence among animals underscores the need for integrated, climate-informed, One Health surveillance. Predictive modeling and regionally harmonized strategies are critical for preventing cross-species spillovers and managing future zoonotic threats under changing climatic conditions.