Sarcocystis Species: Humans as Final Hosts

Sarcocystis suihominis and S. bovihominis

Name

Greek: sarx = meat, flesh; kystos = cyst. Latin: sus = porc, pig; homo = human; bos = cattle; Miescher’s tubes = long cysts in muscle fibers detected by the swiss scientist Miescher (1811–1887).

Geographic Distribution/Epidemiology

Worldwide, probably several hundred million humans are infected from time to time. However, only rather few show clear significant symptoms for a short period of 24 h after an infection.

Morphology/Life Cycle

Infections occur with S. suihominis and S. bovihominis, if humans eat raw or undercooked meat of pigs respectively cattle that contains tissue cysts of these two species (Figs. 1, 2, 3, and 4). These cysts contain cystozoites (Fig. 4) and are characterized by different types of protrusions of the primary cyst wall. In the intestine of humans the cystozoites are set free and enter the intestinal wall. Inside the cells of subepithelial layer (lamina propria) gamogony starts and gives finally rise to fully...