Ticks of the Ixodidae family as reservoir hosts for arboviruses in the Republic of Guinea. II. Arboviruses

Abstract

From 1978 to 1985, 96 167 Ixodidae family were collected, from which 79 strains of the following arboviruses were isolated, i.e. 4 Bhanja strains, 9 CHF-Congo, 20 Dugbe, 24 Jos (viruses ecologically related to ticks), 10 Abadina, 7 Bluetongue, 1 Bunyamwera, 1 Chikungunya, (related to ticks for the first time), 1 Kindia and 2 Forecariah (new viruses). The main sources for arbovirus isolation were ticks of the Amblyomma varíegatum genus (78,5 %) followed by ticks of the Boophilus (12,6 %), Rhipícephalus (7,6 %) and Haemaphysalis (1,3 %) genera. According to experimental data obtained in the laboratory and in the field involvement of A. variegatum as reservoir host for Abadina virus was established. The seasonal dynamics characteristics of the propagation of this virus and its pathogenicity for cattle were also noticed. Serological surveys on cattle (i.e. on about 7000 sera) showed that Abadina, Bluetongue, CHF-Congo, Dugbe viruses spread more actively, with 24-35 % positive sera. The rate of positive sera against Bhanja, Forecariah, Jos and RVF viruses did not exceed 0,9 %. During the study period, the arboviruses isolated from ticks did not play any important epidemiological role in human pathology of the Republic of Guinea.