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.
Animals ; *Camels ; Esophagus/parasitology ; Female ; Heart/parasitology ; Iran/epidemiology ; Male ; Muscle, Skeletal/parasitology ; Prevalence ; Sarcocystis ; Sarcocystosis/complications/epidemiology/*veterinary

The present study surveyed the prevalence of natural infection of the sheep esphagus muscle with sarcocysts of Sarcocystis ovicanis and examined induction of protective immunity using UV-attenuated sporocysts. The overall prevalence of natural infection of the sheep was 95%. Infectivity of the collected sarcocysts was confirmed by shedding of sporulated oocysts after feeding infected esophageal tissues to dogs. To induce protective immunity, lambs were immunized 3 times (once a week) with 1.5 x 10(4) sporocysts exposed to UV-light for 30 min (UV-30 group) or 60 (UV-60 group) min and then challenged with 1.5 x 10(4) normal sporocysts at the 3rd week post the 1st vaccination. These lambs showed high survival and less clinical signs of sarcocystosis than normal infected lambs. The attenuated sporocysts produced abnormal cysts; small in size and detached from the muscle fiber. These abnormalities were more obvious in UV-60 group than UV-30 group. Also, the IFN-gamma level and lymphocyte percentage were increased while the total leukocyte count was decreased in the UV-60 group compared with other groups. The high level of IFN-gamma may be an evidence for the induction of Th1 responses which may have protective effect against a challenge infection.
Animals ; Dogs ; Esophagus/parasitology ; Feces/parasitology ; Interferon-gamma/secretion ; Lymphocytes/immunology ; Oocysts/*immunology ; Peptide Fragments/secretion ; Prevalence ; Protozoan Vaccines/immunology ; Sarcocystis/cytology/*immunology/*radiation effects ; Sarcocystosis/epidemiology/immunology/prevention & control/*veterinary ; Severity of Illness Index ; Sheep/immunology/parasitology ; Sheep Diseases/immunology/*prevention & control ; Survival Analysis ; *Ultraviolet Rays ; Vaccines, Attenuated/immunology