Sarcocystis infection in domestic and wild avian hosts: Inseparable flight partners

Sarcocystis infections have been reported from numerous avian species. A remarkable number of valid Sarcocystis species infecting birds have been identified and named having avian species as intermediate hosts (n = 32). Only 14 species have their complete biological cycle known due to the difficulties in conducting in vivo experiments. In addition, at least 16 Sarcocystis species have been confirmed by molecular techniques to use birds as their definitive hosts. The present paper reviews recent findings in the field and remarks on the contribution of molecular tools to unravel important aspects of the epidemiology of the genus. Clinical diagnosis is discussed. Three Sarcocystis species, Sarcocystis falcatula, Sarcocystis calchasi, and Sarcocystis halieti have wide host range and cause clinical sarcocystosis in many avian species. Limitations of currently available molecular markers and animal experimentation to distinguish closely related Sarcocystis species are discussed.