Abstract:The prevalence of Sarcocystis spp. was investigated by gross and histopathological examinations in 250 camels (Camelus dromedarius) slaughtered from 2002 to 2005 in the Mashhad Slaughterhouse, eastern Iran. Samples were taken from the diaphragm, heart, tongue, esophagus and masseter muscles for histopathological studies. No macroscopic sarcocysts were found in the samples at gross inspection. Sarcocysts were detected in 209 of 250 (83.6%) examined camels at histopathological level. The infection rate of the esophagus, heart, masseter muscles, diaphragm, and tongue was 58.8%, 48.0%, 46.8%, 41.6%, and 28.0%, respectively. There was no significant difference in the rate of infection between male (85.8%) and female (81.0%) camels. The tissue response to vital cysts was minimal; however, reaction to the degenerating cysts was severe and caused tissue damages resulting in hyperemia, hemorrhages, mononuclear cell infiltration, necrotic changes, and fibrosis. The wild and domestic carnivores especially dogs may be the final hosts of Sarcocystis spp. in this area.

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.

In the present study, Echinoccocus granulosus isolates collected from camels (Camelus dromedarius) in eastern Iran were characterized based on the nucleotide sequences of mitochondrial CO1 and NDI genes. The molecular results for camel isolates demonstrated that at least 2 different genotypes are present, i.e., a buffalo genotype (G3) and the camel genotype (G6). Although the sequences of the Iranian camel genotype (G6) are completely homologous to the reference sequence of G6 (M84666) of E. granulosus , a nucleotide mutation (C to T at position 168) was detected in the CO1 sequences of the Iranian G3 isolates (HM626405) when compared with the reference G3 genotype (M84663). The findings of the present study represent the demonstration of the buffalo strain in camels. As previously reported, humans can be infected by this genotype; accordingly, the epidemiological importance of this genotype in the camel population should be considered in further studies.