Ecology of ticks as potential vectors of Crimean-Congo hemorrhagic fever virus in Senegal: epidemiological implications

Abstract

At least 30 tick species from 7 genera have been found naturally infected with Crimean-Congo hemorrhagic fever (CCHF) virus worldwide. To this list we add Rhipicephalus guilhoni. In the sub-Saharan Africa, 17 tick species have been implicated as vectors, of which 12 are present in Senegambia or Mauritania. We studied the five principal species that appear to be the most important in CCHF virus transmission in Senegal, namely Amblyomma variegatum, Hyalomma impeltatum, H. marginatum rufipes, H. truncatum, and Rhipicephalus guilhoni. We report on the distribution, host associations, seasonal activity patterns and CCHF virus infection of these ticks, as well as the epidemiological implications for human disease. Despite similarities in ecological characteristics, not all of these species are equally likely to be important in the transmission cycle. The most important vectors in enzootic and epidemic transmission throughout Senegal appear to be Hyalomma truncatum and Amblyomma variegatum.