Transmission of Ife virus by Aedes aegypti mosquitoes was investigated. Mosquitoes were experimentally infected by feeding on viraemic mice or on infected mouse brain suspended in defibrinated chick blood. Normal infant mice were exposed to infected mosquitoes after predetermined extrinsic incubation period. Ife virus persisted for only 1 day in mosquitoes that fed on viraemic mice and for 5 days in those that fed on infected brain/blood suspension. Virus was not recovered in infant mice exposed to infected mosquitoes. However, there was serological evidence of virus transmission manifested as the presence of complement fixing antibody against Ife virus in mice exposed after 2 days and 2–5 days extrinsic incubation periods to mosquitoes infected by feeding on viraemic mice and by feeding on infected brain/blood suspension respectively. This transmission was considered mechanical in view of the short virus persistence and extrinsic incubation periods.
