Seroprevalence of Trypanosoma evansi infections among dromedary camels (Camelus dromedaries) in North Al-Sharqiya governorate, Sultanate of Oman

Trypanosoma evansi is a well-known hemoprotozoa that infects diverse domestic and wild animals worldwide and caused devastating disease called surra. This research aimed to investigate the seroprevalence of Trypanosoma evansi and its associated risk factors in dromedary camels in North Al-Sharqiya governorate in the Sultanate of Oman.  A total of 4364 serum samples was collected from three willayat in north governorates of Sultanate of Oman; Ibra (926, 21.2%), Qabil (1119, 25.6%) and Bidiyah (2319, 53.1%). Samples were examined for the presence of antibodies against T. evansi using card agglutination test (CATT/T. evansi). Binary logistic regression was used to study the association of T. evansi seroprevalence and risk factors such as location, gender, purpose and age of camels. The overall seroprevalence of T. evansi detected by CATT/T. evansi test was 38% (1659/4364, CI: 36.6-39.5%). There was a significant difference (p=0.001) between location and T. evansi seroprevalence, whereas highest seroprevalence was found in Ibra (49.9%, CI: 46.7-53.1%) followed by Bidiyah (35%, CI: 33-36.9%) and Qabil (34.5%, CI: 31.8-37%). Camels from Ibra were almost two times more likely to have circulating antibodies of T. evansi than camels from Bidiyah (OR=1.89, CI: 1.591-2.168). Also, the results showed a significant difference between seroprevalence and sex (p=0.023), whereas the age of camels was not (p>0.05). To our knowledge, this is the first research that indicated that T. evansi antibodies were circulating among camels in Oman, and further research needs to be tackled to study the molecular characterization of T. evansi and its prevalence in other animal species. Furthermore, cross-sectional studies of T. evansi from different regions in Oman warrant further investigation.