Prevalence and pathology of camel filariasis in Iran.

A total of 1,070 camels of different ages and of both sexes slaughtered at Mashhad slaughterhouse were inspected for infection with Dipetalonema evansi. Microfilariae were found in peripheral blood smears of 221 (20.7%) camels (14% females and 23% males). In a second study, the testicles, epididymises, spermatic cords, and lungs of 197 male camels were examined, and 165 (83.7%) were infected with adult forms of D. evansi. Tissue sections from 30 infected and ten uninfected camels were collected and processed routinely for further histopathological studies. The arteries infected with D. evansi in the region of nodules in testis showed chronic reaction characterized by proliferative and hyperplastic changes of the endothelial and fibrous connective tissue layers, narrowing the lumen or occluding it. The testicles were either hypertrophic or atrophic and showed chronic orchitis with infiltration of lymphocytes, eosinophils, macrophages and fibroblasts, parenchymal degeneration, and necrosis and, in some cases, with hematoma and hydrocele formation. Necrosis of the alveolar walls, atelectasis, pulmonary edema, and fibrosis of the pulmonary parenchyma with chronic interstitial pneumonia and rarely mineralization of the wall of the blood vessels were also seen in some of the infected animals. D. evansi is highly endemic and constitutes an important health problem to camels in this area, resulting in high morbidity, impaired working capacity, and lowered productivity.