Multi-country study finds RVF exposure in East and Central Africa; higher seroprevalence in Uganda than DRC and Kenya
A two-year, multi-site study of febrile patients in DRC, Kenya and Uganda detected Rift Valley fever exposure in 5.3% of participants overall, with 10.4% seropositivity in Uganda, 2.0% in Kenya and 1.4% in DRC.
A two-year longitudinal study across six health facilities in the Democratic Republic of the Congo (DRC), Kenya and Uganda assessed human exposure to Rift Valley fever virus (RVFV) among febrile patients aged 10 years and older. The investigation aimed to determine whether the absence of reported human outbreaks in eastern DRC reflects true absence of virus circulation or undetected transmission.
Between 2021 and 2024 the study enrolled 4,806 participants: 1,370 (28.5%) in the DRC site, 1,468 (30.6%) in Kenya and 1,968 (40.9%) in Uganda. Inclusion criteria required febrile subjects with fever lasting seven days or less who had not responded to treatment. Exclusion criteria included urinary tract infection, COVID-19 or other conditions explaining the febrile illness, and hospitalization for more than 48 hours in the prior 14 days.
Venous blood samples were collected in SST and EDTA tubes and tested for RVF virus RNA and anti-RVF antibodies. Across all sites 253 participants (5.3%) tested positive by serological and/or molecular assays. Country-level results were 19/1,370 (1.4%) in the DRC, 29/1,468 (2.0%) in Kenya and 205/1,968 (10.4%) in Uganda.
The study design permitted up to 20% of participants to have possible malaria co-infection. Pregnant women were included because of documented abortive effects of RVF in livestock, although human data on pregnancy outcomes remain limited. Investigators collected de-identified socio-demographic, clinical, household, behavioral and knowledge data using electronic REDCap questionnaires.
Researchers targeted enrollment of 1,600 participants at the single DRC site over two years and 707 participants per site in Kenya and Uganda. The paper highlights heavy rainfall and flooding as environmental predictors of RVF risk and frames the findings in the context of outbreak-prone settings versus regions with few reported human cases.
The article is published as an uncorrected proof in PLOS Neglected Tropical Diseases (March 10, 2026) and reports collaboration among institutions in Belgium, the United States, DRC, Kenya and Uganda. Methods and results sections follow standard journal reporting, including RNA and antibody testing and detailed data management roles among authors.