Preliminary study on potential mechanical vectors of animal trypanosomes in the Far North region of Cameroon

An entomological study was carried out in the Far North region of Cameroon – historically known focus for animal trypanosomosis and declared tsetse free in the late 1970s – to determine the potential mechanical vectors for trypanosomes and their spatial preference in this region. Thirty-one Nzi traps were installed at 6:30–8:00 a.m. in Goulfey, Madiako canton and Darack karena in Logone and Chari Division, as well as in Guidiguis, Kalfou and Maga-Guirvidig in two other divisions. They were visited after 10–11 hours of exposition. The sampling lasted one day. A total of 20,084 hematophagous flies (865 Stomoxys and 19,219 tabanids) were collected. Stomoxys niger was the only Stomoxyinae species caught, whereas five species of tabanids were collected: Atylotus agrestis, A. albipalpus, A. fuscipes, Tabanus taeniola and T. biguttatus. A. agrestis was by far the most prevalent species (92.7%), followed by T. taeniola (7.1%). The apparent densities of 50.1, 409.4 and 1499.0 tabanids per trap per day in Guidiguis, Goulfey and Madiako canton, respectively, were significantly different (p = 0.0002). Tabanids were more abundant in campsites than in pastures and water points. Atylotus agrestis seemed to be the major potential mechanical vector of trypanosomes in the area.