O’nyong-nyong Virus Infection Imported to Europe from Kenya by a Traveler

To the Editor: O’nyong-nyong virus (ONNV) is a mosquitoborne RNA virus of the Togaviridae family. The virus was first isolated in June 1959 from serum samples from febrile patients in the northern province of Uganda (1). Unlike ONNV is primarily transmitted by anopheline mosquitoes (2). ONNV is genetically and serologically related to chikungunya virus (CHIKV) (1), but is restricted to the African continent. The clinical picture resembles CHIKV infection, i.e., a self-limited febrile illness characterized by headache, rash, and joint pain. In contrast to CHIKV, ONNV is reported to cause lymphadenopathy more often and affected joints do not show effusions (3).