Epidemiology and Detection of Multiple Drug-Resistant Trypanosoma congolense in Zebu Cattle in Gurage Zone, Southwest Ethiopia

Abstract

Background Trypanosomosis in animal is a major threat for the development of livestock sector in many Africa countries as a result it contributes for the prevailing severe hunger and poverty in most sub-Saharan African countries. The aim of this study is to determine the prevalence and drug susceptibility pattern of Trypanosoma congolense in selected districts in Gurage zone, Ethiopia. Methods A cross-sectional study was carried out in 2000 selected indigenous cattle and eighty (n=80) cattle were selected out of 2000 to carry out drug susceptibility test using longitudinal study. Animals were grouped equally into two (n=40) treatment groups and treated with isometamidium chloride (ISMM) and diminazene aceturate (DIM) according to the manufacturer’s instruction. Sample was collected and the microhaematocrit centrifugation technique was used to determine PCV while trypanosomes were detected using dark-ground phase-microscopy. Results The overall prevalence of trypanosomosis was 4.50% (95% CI=4.28, 4.72) and significantly different among districts (P<0.05) where the highest prevalence (7.1%) was recorded in Abeshege district. The mean PCV for cattle in the longitudinal study (n=80) was 23.2 (95%CI=22.3, 24) with no significance (P>0.05) among the study villages. An overall 37.5% (30/80) drug failure rate was recorded at day 14 post treatment. The failure rate accounted 27.5% (11/40) and 47.5% (19/40) for ISMM and DIM at 14 days post-treatment respectively. Those persistently infected cattle at day 14 were re-treated by exchanging the drug and revealed a failure rate of 26.3% (5/19) and 54.5% (5/11) for ISMM and DA respectively. The mean PCV was variable (P<0.05) before applying treatment (day 0=23.2) and day 28 (PCV=25.09). Conclusions The study revealed that T. congolense developed resistance to ISM and DIM at the given dosage regimen. Therefore, an integrated control approach against the parasite and vectors should be implemented in the area.