Dynamics of African tick (Acari: Ixodoidea) populations in a natural Crimean-Congo hemorrhagic fever focus.

Abstract

A study of ticks collected from large and small mammals and from vegetation in an area where Crimean-Congo hemorrhagic fever (CCHF) virus was found was carried out over 3 yr. Three two-host species of ticks, Hyalomma marginatum rufipes Koch, Hyalomma truncatum Koch, and Rhipicephalus evertsi evertsi (Neumann), were abundant; and three other species, Amblyomma marmoreum Koch, Margaropus winthemi Karsch, and Argas, undescribed sp., were less frequently encountered. Immatures of H. m. rufipes and H. truncatum showed two peaks of activity, one in July and one in November; adults were most active during December, January, and February. A similar pattern of seasonal activity was found for larvae and nymphs of R. e. evertsi, which showed peaks in their occurrence in May and in October/November. H. m. rufipes adults were more common on eland and Burchell's zebra, but H. truncatum preferred black wildebeest. Immature stages of these species also showed host preference. H. truncatum was very common on rodents and hares and absent from guinea fowl; H. m. rufipes was found on guinea fowl and also on hares, but not on rodents. Seasonal activity of ticks, the hosts with which they are associated, and their role in the epidemiology of CCHF are discussed.