EXPERIMENTAL TRANSMISSION OF CRIMEAN-CONGO HEMORRHAGIC-FEVER VIRUS BYWEST-AFRICAN WILD GROUND-FEEDING BIRDS TO HYALOMMA-MARGINATUM-RUFIPESTICKS

Hyalomma (H.) marginatum rufipes ticks commonly infest birds and are p otential vectors of Crimean-Congo hemorrhagic fever (CCHF) virus in we st Africa. An experimental model for investigating the role of birds i n the CCHF virus transmission cycle was developed. Following CCHF viru s inoculation, antibodies were detected by enzyme-linked immunosorbent assay in one red-beaked hornbill and one glossy starling, but not in two laughing doves and six domestic chickens. None of the birds showed a detectable viremia. Hyalomma marginatum rufipes larvae were placed on three red-beaked hornbills and one glossy starling. These birds wer e then inoculated with CCHF virus (10(15) 5 50% mouse intracerebral le thal doses). Virus transmission to larvae or nymphs was obtained and s eroconversions in birds were recorded. Virus was also detected in 90% of the individually tested nymphs, as well as in adults. The virus was then successfully transmitted by adult ticks to rabbits and the engor ged females were allowed to oviposit. Progeny larvae were placed on an other group of birds and one of three birds showed seroconversion. The cycle of transmission of virus between ticks and aviremic ground-feed ing birds represent a potential reservoir and amplification mechanism of CCHF virus in west Africa.