Submitted to: Experimental Parasitology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/1/2012
Publication Date: 5/1/2012
Citation: Chen, X., He, Y., Yonghua, L., Olias, P., Rosenthal, B.M., Cui, L., Zuo, Y., Yang, Z. 2012. Infections with Sarcococystis wenzeli are prevalent in the chickens of Yunnan Province, China, but rare or absent from the flocks of domesticated pigeons and ducks. Experimental Parasitology. 131(1):31-34. Interpretive Summary: Parasites in the genus Sarcocystis infect a wide variety of animals, including lifestock. These impose losses to agricultural productivity, and some of them can induce infection in human beings. The distribution and diversity of such parasites in poultry is poorly known in China. Therefore, this study was conducted to survey the distribution of such parasites in a sample of chickens, ducks, and pigeions. Sarcocystis wenzeli was identified in 8.8% of chickens, but not in co-located flocks of other types of fowl. This study clarifies the epidemiology of this parasite, which appears limited to chickens in this region, and should be of interest to poultry producers, veterinarians, and food safety authorities.
Technical Abstract: The distribution and prevalence of infections with species of Sarcocystis in domestic fowl in Asia are poorly known. Here, ducks, pigeons, and chickens from Yunnan Province, China were examined for evidence of parasitic infection with Sarcocystis spp. One hundred ninety one chickens, 514 ducks, and nine pigeons were investigated. Whereas the ducks and pigeons lacked tissue cysts in their muscle, brain or peripheral nervous system, cysts of Sarcocystis wenzeli were identified in 17 of 191 chickens (8.8%). Morphologically, the cysts were thread-like, ranging is size from 334-3169×41-117µm (mean 1093×65µm). Cysts were septate with dense, short finger-like protrusions which appeared radically striated. The cyst wall was 1.4-3.5µm (mean 2.4µm) thick. The bradyzoites were lancet shaped and measured 12.2-17.7×1.8-2.9µm (mean 14.6×2.5µm). Ultrastucturally, the primary sarcocyst wall had stubby villar protrusion, corresponding to the ‘type 9’ class previously designated. The protrusions measured 0.87-1.89×0.47-0.91µm (mean 1.27×0.59µm; n= 57). These findings confirm previous work from the vicinity of Kunming concerning the occurrence of S. wenzeli in chickens, but indicate that corresponding infections may not occur in the regional domestic flocks of other types of fowl.