Submitted to: Journal of Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 10, 1999
Publication Date: N/A
Interpretive Summary: Sarcocystis falcatula is a single-celled parasite. It can cause mortality in small avian species such as sparrows, finches and budgerigars. Birds become infected with Sarcocystis falcatula by ingesting the resistant stage of the parasite (sporocysts) excreted in the feces of infected opossums. Sarcocystis falcatula infections have not been reported in countries other than the United States. Scientists at the Beltsville Agricultural Researc Center report for the first time S. falcatula infection from Argentina. These results will be of interest to parasitologists, pathologists, and zoo veterinarians.
Sarcocystis sporocysts from the intestines of 4 opossums (Didelphis albiventris) from Argentina were identified as Sarcocystis falcatula based on schizogonic stages and pathogenicity to budgerigars (Melopsittacus undulatus). Seven captive-bred budgerigars fed sporocysts from the opossum feces died of acute sarcocystosis 8, 9, 11, 12, and 14 days after inoculation. Schizonts and merozoites found in the lungs and other organs of the budgerigars were identified as S. falcatula based on structure and immunoreactivity with S. falcatula specific antibody. Sarcocystis falcatula was also isolated in bovine monocyte cell cultures inoculated with lung tissue from a budgerigar that died 9 days after ingesting sporocysts. Two budgerigars inoculated subcutaneously with 1000000 culture derived S. falcatula died 11 and 12 days post-inoculation. This is the first report of S. falcatula infection in South America.