Diminazene-resistant Trypanosoma vivax in West African Dwarf lamb, south-west, Nigeria: A case report

Abstract

A case of diminazene-resistant trypanosomosis in a West African Dwarf (WAD) lamb with no previous record of trypanocidal therapy is reported. Lamb was presented with clinical manifestations that included lethargy, blanched conjuntival mucous membrane, emaciation and exhaustion. Pre- and post-trypanocidal treatment evaluation of blood parasitologically by direct microscopy revealed parasitaemia of 31x10⁶ and 15x 10⁶/ml of blood respectively. Specie specific Polymerase Chain Reaction (PCR) and gel electrophoresis of the PCR products revealed amplicons size of 400 bp, expected size of Tryopanosoma vivax. The trypanosomes isolated obtained from the lamb before treatment was passaged into a haemoparasite free sheep. Pre and post reinfection chemotherapy of isolated trypanosomes into haemoparasite free sheep showed parasitemia of 7.5 x 10⁶ and 15x 10⁶/ml of blood respectively. Epidemiological survey of sheep environment showed moderate infestation of Glossina palplispalplis precipitated by the incursion of different herd’s of Fulani cattle with the history of indiscriminate use of drugs; grazing their animals in the immediate vicinity of the flock. This report confirms the presence of diminazeneaceturate resistant T. vivaxstrain in the study area and also discussed the clinical implication of drug resistance trypanosomosis.

Keywords: Dwarf lamb, T. vivax strain, drug resistance