Structure, composition, and roles of the Toxoplasma gondii oocyst and sporocyst walls

Toxoplasma gondii is a coccidian parasite with the cat as its definitive host but any warm-blooded animal, including humans, may act as intermediate hosts. It has a worldwide distribution where it may cause acute and chronic toxoplasmosis. Infection can result from ingestion either of tissue cysts in infected meat of intermediate hosts or oocysts found in cat faeces via contaminated water or food. In this review, we highlight how the oocyst and sporocyst walls sustain the persistence and transmission of infective T. gondii parasites from terrestrial and aquatic environments to the host. We further discuss why targeting the oocyst wall structure and molecules may reduce the burden of foodborne and waterborne T. gondii infections.