Note on Onchocerca armillata in the Sudanese camel (C. dromedarius). A histological and anatomo-pathological approach.

Aortic onchocercosis due to O. armillata was diagnosed in 45 (41%) out of 109 Sudanese camels. Although the thoracic aorta was regularly affected, involvement of other vessels such as the abdominal aorta, brachiocephalic, pulmonary and costocervical arteries was not excluded. Gross examination of the affected blood vessels revealed tortuous tunnels of parasitic tracks readily visible in the intimal surface of the vessels. Nodular lesions were more common on the adventitia. Microscopically, the lesions showed irregulary elevated intimal surfaces. The underlying tunica media contained a varying number of encapsulated and partially mineralized parasitic fragments. The inflammatory response varied in intensity and location and consisted of eosinophils, lymphocytes, macrophages and occasional giant cells.