Sarcocystis spp. – an underestimated parasite with zoonotic potential associated with food of animal origin

Abstract

The protozoa of the genus Sarcocystis are worldwide distributed parasites affecting a wide range of animals. They life cycle requires two hosts: definitive and intermediate. Over 250 species of Sarcocystis have been described but three of them are known to have a zoonotic potential. These are: S. hominis, S. heydorni and S. suihominis. Domestig pigs and wild boars can be intermediate hosts for S. suihominis, wheras cattle for S. hominis and S. heydorni. Therefore, people can become infected after eating raw or insufficiently heat-treated pork, wild boar meat or beef. Human sarcocystosis is generally asymptomatic but in some cases can induce the syptoms of intestinal illness. People can also become accidental intermediate hosts after ingesting sporocysts from feces-contaminated food or water leading to muscular sarcocystosis. The cysts of Sarcocystis spp. (sarcocysts), which with some exceptions, are not visible and therefore they are rarely detected during routine veterinary meat inspection consisting of visual assessment of muscle tissue and digestion (in case of examination of pig and wild boar meat). The presence of visible cysts of Sarcocystis spp. can lead to meat condemnation and it generates economic losses for farmers. Food safety regulations require the control of the parasites presence in meat intended for human consumption but there are no regulations regarding the control of Sarcocystis spp. Nevertheless, European Food Safety Authority (EFSA) encourage to monitor and characterise Sarcocystis ssp. in animal and foodstuffs.