Microscopical and serological studies on Sarcocystis infection with first report of S. cruzi in buffaloes (Bubalus bubalis) in Assiut, Egypt.

This study was performed for the purpose of investigating the prevalence and the species composition of Sarcocystis spp. in buffaloes in Assiut province, Egypt. Macroscopically we reported the infection of buffaloes with Sarcocystis fusiformis, while microscopically three Sarcocystis species (Sarcocystis cruzi, Sarcocystis levinei and Sarcocystis hominis) cysts were recognized, and were differentiated by their morphological features using both histopathological sections and electron microscope scanning. Regarding the prevalence of Sarcocystis species among buffaloes in Assiut province, we reported that, using gross examination of 90 buffaloes' esophagus, only 23 samples out of 90 (25.5 %) were found to be infected; on the other hand, by using microscopical examination, the prevalence was 27.7 % (25 samples out of 90 samples were found to be infected). Using ELISA, 85 samples out of 90 (94.4 %) were found positive, an overall prevalence of 94.4 %. In this work we concluded that customary meat inspection methods in abattoirs in Egypt are insufficient for detecting Sarcocystis infection. Due to the presence of hidden or microscopic cysts, we strongly recommend the use of combined microscopical examination and ELISA for Sarcocystis diagnosis, to avoid human infection of such zoonotic parasite and to control the consequent disease. In addition, this study introduced the first report of S. cruzi in buffaloes in Egypt, and proved the hypothesis that S. cruzi is able to use animals such as water buffalo as intermediate hosts.