Prevalence and Drug Sensitivity of Trypanosome Isolates from Slaughter Animals to Diminazene and Isometamidium in Sub Humid Tropical Zone of Southeastern Nigeria

摘要

A total of 465 animals comprising 116 goats, 155 pigs and 194 cattle presented for slaughter at Nsukkamunicipal abattoir were screened for trypanosomosis between March and June, 2011. Whole blood from theanimals was examined by wet mount, stained smear and Buffy coat methods. The packed cell volume (PCV) wasalso determined. Samples positive for trypanosomes were inoculated into donor mice and mice for the drugsensitivity tests were infected. Twelve (12) mice were used for drug sensitivity test of each isolate. The micewere infected with 1 x 105 trypanosomes each and further divided into 4 groups of 3 each treated withdiscriminatory doses of 7.0 mg/kg, 28 mg/kg of diminazene aceturate (DA) and 1 mg/kg, 8 mg/kg ofIsometamidium chloride (ISMC). Infected mice were treated 7 days post infection following parasitaemia. Theresults showed an overall prevalence of 19 (4.08%) comprising, 9 (5.81%) for pigs, 6 (3.09%) for cattle and 4(3.44%) for goats. Infected animals had a significantly lower (p<0.05) PCV than uninfected ones. The isolateswere predominantly Trypanosoma brucei (T.brucei) was78.9% especially in pigs. The T. brucei isolates showedsensitivity only to the high doses of diminazene aceturate and Isometamidium chloride. However, only 2isolates were resistant to isometamidium at 1 mg/kg whereas all the 10 isolates showed variable degrees ofresistance to diminazene aceturate at 7.0 mg/kg. The current study concluded that populations of trypanosomesresistant to diminazene aceturate exist and abound in our environment.