Parasitological, serological and molecular survey of camel trypanosomiasis in Somalia.

Background: Camel trypanosomiasis or surra is of great concern in Somalia, since the country possesses the largest one-humped camel (Camelus dromedarius) population in the world. Civil war in Somalia has resulted in the destruction of educational, research, economic and social structures, making the country scores very low for most humanitarian indicators. Previous studies on detection of Trypanosoma species in Somali camels have only been performed during the 1990s using standard trypanosome detection methods (STDM). Considering the lack of state-of-the-art knowledge on camel trypanosomiasis in Somalia, the present study aimed to assess the prevalence of Trypanosoma spp. in three districts of Somalia.

Methods: A total of 182 blood samples from C. dromedarius from nomadic and dairy farms were evaluated using STDM, serological (CATT/T. evansi) and molecular (ITS1-PCR) methods.

Results: All samples were negative for Trypanosoma spp. by STDM. A total of 125/182 (68.7%, 95% CI: 61.4-75.3%) camels were seropositive for T. evansi by CATT/T. evansi. Camels reared in nomadic system were more likely to be seropositive for T. evansi than those under dairy production system (OR: 5.6, 95% CI: 2.1-15.2, P = 0.0001). Five out of 182 (2.7%, 95% CI: 0.9-6.3%) camels tested positive for Trypanosoma sp. by ITS1-PCR. Sequencing of the ITS1 region of the Trypanosoma species detected herein revealed that camels were infected with T. evansi and T. simiae.

Conclusions: Trypanosoma evansi is highly prevalent in camels from the Banadir region of Somalia, particularly in nomadic herds. To our knowledge, this is the first study to confirm infections with T. evansi and T. simiae in Somali camels through DNA sequencing. Our data highlight the need for implementation of adequate control measures aiming to reduce the impact on camel production in the country.