Sarcocystis and Its Complications in Camels (Camelus dromedarius) of Eastern Provinces of Iran

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.

Sarcocystis infection and actinomycosis in tumorous eosinophilic enterocolitis.

Intramural masses were resected from jejunum and ileocecal portion of a 49-year-old, female patient with partial gut obstruction. Histopathological examination indicated the masses to be tumorous eosinophilic enterocolitis. Recent and late development phases of Sarcocystis in relation to bradyzoite infection have been observed and considered to be responsible for eosinophilic inflammation. Concomitant intestinal actinomycosis, known to produce tumorous lesion without eosinophilia, appears as an attractive natural model in producing tumorous eosinophilic enterocolitis. Pertaining to parasitic development, it is suggested that persisting sporulated oocyst may undergo spontaneous excystation in the host's intestinal wall, along with complex sporogony.

Combined Sarcocystis and gram-positive bacterial infections. A possible cause of segmental enterocolitis in Thailand.

Between 1981 and 1990, 22 intestinal specimens surgically resected due to segmental enterocolitis were collected and examined. Grossly, the specimens were classified into 3 groups 1) Acute inflammation with hemorrhage and necrosis 2) Constrictive lesion 3) False diverticulum with perforation. Mostly, there was unisegmental involvement, distributed in jejunum, ileum and ileocolon. Microscopically, small parasitic structures, interpreted to be unconventional excystation stage of Sarcocystis hominis, (Railliet and Lucet, 1891) Dubey 1976, were present on the luminal border and within the crypt-lining epithelial cells. At the ulcerated area, tissue invasion by Gram-positive bacteria were always seen and considered as second pathogen. Source of the parasite was likely from cyst-containing beef available in markets, (Bos indicus and Bubalus bubalis) along with consumption of undercooked beef. Antismooth muscle antibody, IgG class, with the titer ranging from 1:16-1:256 were detected in 45 per cent of the patients. This is considered as autoimmunity against intestinal smooth muscle damaged previously from subclinical inflammatory condition. Present information suggests a long-standing existence of Sarcocystis in the patients' intestine, associated with Gram-positive bacterial infection, as the mechanism producing segmental enterocolitis found in the Central region.

Sarcocystis infection in an Orang Asli: the second human case from Malaysia.

The second case of Sarcocystis infection in man is reported from an aborigine girl. It was an incidental finding at autopsy and two cysts were seen in the muscle of the oropharyngeal region. The cysts and zoites were similar to those in the previous case reported from Malaysia.