On November 23rd, 2021, Rwanda Biomedical Centre (RBC) was alerted through media of an unknown illness that was causing an increase in patient presentations to Simbi Health Center (HC) the Southern Province, Rwanda; the HC recorded 96 patients in 7 days, usually family entities. Patients presented with high grade fever, headache, general body weakness, abdominal pain, diarrhea and vomiting. A team composed of four Field Epidemiology Training Program (FETP) residents and two RBC staff were deployed to investigate a possible outbreak, identify the source of the infection, and initiate appropriate control measures. 