Parasitological and serological study of camel trypanosomosis (surra) and associated risk factors in Gabi Rasu Zone, Afar, Ethiopia

Camel trypanosomosis (surra), caused by Trypanosoma evansi, is the most important single cause of morbidity and mortality in camels. Thus, a cross-sectional study was conducted from February to June, 2012 to investigate the parasitological and serological prevalence and associated risk factors of camel trypanosomosis in two camel rearing districts of Gabi Rasu zone, Afar region, Ethiopia. A total of 408 randomly selected camels reared under extensive husbandry management system were sampled for this study. Parasitological and serological examination was carried out by using haematocrit centrifugation technique (HCT) also known as Woo’s technique and card agglutination test for trypanosomes (CATT/T. evansi), respectively. The overall parasitological and serological prevalence of camel trypanosomosis was found to be 5.15 and 23.77%, respectively. Nine out of twenty one camels that scored positive by the haematocrit centrifugation technique (HCT) test were negative by card agglutination test for trypanosomes (CATT/T. evansi), and the relative sensitivity of CATT/T. evansi test was found to be 57.14% (12/21). The mean packed cell volume (PCV) of parasitologically negative camels (24.27 ± 0.18) was significantly higher (p < 0.05) than that of parasitologically positive camels (20.71 ± 0.58). Serologically negative camels had a mean PCV of (24.27%) which was not significantly different from that of positive camels (23.48%). Risk factors associated with parasitological and serological prevalence were found to be “study district” and “age”. Accordingly, camels in Awash Fentale district had significantly higher (p < 0.05) parasitological and serological prevalence of camel trypanosomosis than in Amibara district. Generally, surra was found to be prevalent in Awash Fentale district during the study period. Therefore detailed studies should be carried out on the seasonality of the disease and its vectors in order to establish the clear epidemiology of the disease.