Fatal toxoplasmosis in a captive squirrel monkey ( Saimiri boliviensis ) in Portugal

New World monkeys are especially vulnerable to develop severe clinical manifestations and succumb to acute toxoplasmosis. This study aimed to describe the histopathological findings and genotypic characterization of the Toxoplasma gondii strain involved in a lethal case occurring in a zoo-housed black-capped squirrel monkey ( Saimiri boliviensis ) in Portugal. Cyst-like structures suggestive of Sarcocystidae parasites and acute injuries in liver and brain were observed by light microscopy examination. By immunohistochemistry, calprotectin, T. gondii antigen and Iba1 antigen had a positive signaling in lung, liver and brain tissues. Toxoplasma gondii B1, ITS1 and 529 repetitive element fragments amplifications together with the genotyping of 13 microsatellite markers confirmed a systemic T. gondii infection linked to a non-clonal type II strain. This description is consistent to the majority T. gondii strains circulating in Europe.