evidence: The investigation was mounted in response to the recently declared outbreak in bordering Moyo district, Uganda. During the investigation, the team collected 41 blood samples from five villages which were in close proximity to the bordering Moyo district, Uganda. Of the 41 individuals whose samples were collected, nine (22%) had history of fever, but none had history of jaundice. The individuals represented a spectrum of occupations typical for the area (farming, forestry, homemaker, soldier). Most of the individuals investigated were between 20-45 years of age, and 18 (44%) of these individuals were female. [...] Public health response - The country rapidly mounted an in-depth multi-disciplinary investigation in Kajo Keji county in response to the cross-border notification of the outbreak in Moyo, Uganda. The investigations included enhanced surveillance, active case finding and entomological surveys from 12-18 February, supported by WHO country office and headquarters.