“Silent” circulation of Trypanosoma spp. in Tabanids (Diptera: Tabanidae) and Cattle in a Tsetse free Range land of Ngaoundere (Adamawa-Cameroon)

Abstract

The Adamawa region falls within the tsetse belt of Cameroon but harbours isolated pockets of tsetse free range lands like Ngaoundere. There is no report on the occurrence of tsetse and bovine trypanosomosis in Ngaoundere. To provide information on this subject, two Vavoua traps were used to trap vectors of bovine trypanosomiasis and at the same time, blood was collected from cattle. Genomic DNA was extracted from buffy coat of cattle blood (n=42) and biting flies (n=53). The nested PCR was used to screen the samples for Trypanosoma spp. During the 14 days of trapping in November and December 2017 in Ngaoundere, 127 flies were documented and classified under two taxa: Tabanidae and Stomoxyini. Three Trypanosoma spp. DNA was isolated from tabanid (18.9%) samples and identified as T. theileri, T. vivax and T. evansi and two of them that is T. theileri (4%) and T. vivax (3%) were also detected in cattle (7%). There was no case of trypanosome DNA isolated from all the screened Stomoxyini. This result indicates the “silent” transmission of T. theileri and T. vivax by tabanids in the absence of glossines in Ngaoundere.