Argasid ticks (2870 ticks divided into 226 pools) collected mainly from nests, chicken houses and burrows were tested for viruses (155 Ornithodoros (Ornithodoros) savignyi, 1422 Alectorobius (Alectorobius (Alectrobius) capensis, 567 Alectorobius (Theriodoros) sonrai, 16 Argas (Persicargas) arboreus, 150 Argas (Persicargas) persicus and 560 Argas (Persicargas) near walkerae). Two tick-borne viruses were isolated: 20 strains of Soldado from Argas capensis, 12 strains of Bandia from Alectorobius sonrai. No strain of arbovirus was obtained from Argas arboreus, Argas persicus, Argas walkerae and Ornithodoros savignyi. Soldado virus was obtained from numerous Alectorobius capensis of Langue de Barbarie National Park (PNLB) where it has caused, with its vector, nesting failure and non-egg hatching in terns colonies. At the same time several Alectorobius capensis from which no arbovirus was obtained, have been involved in a desertion of pelican nesting site in Djoudj National Park of birds (PNOD). The Bandia virus was obtained from Alectorobius sonrai in Bandia.