Immunohistochemical and serological aspects of Toxoplasma gondii infection in Neotropical primates

Toxoplasmosis, a disease caused by the intracellular coccidian Toxoplasma gondii that infects most warm-blooded vertebrates, is widely distributed and fatal for primates, which are peculiarly susceptible for unknown reason(s). Owing to the increasing number of Neotropical mammal deaths where in T. gondii were detected in analyzed tissues, the present immunohistochemical study analyzed the distribution patterns of immunostainings related to this parasite on primates necropsied at the Laboratório de Patologia Animal of Universidade de Passo Fundo (UPF), between the years of 2000 and 2014. Furthermore, a serological survey for the disease was conducted for 21 primates from the UPF Zoo, Rio Grande do Sul, Brazil, belonging to genera Sapajus and Alouatta. In a immunohistochemical test performed using streptavidin-biotin-peroxidase, 26.53% positivity was detected in 98 primates. Immunostainings revealed that infection differed among the lung (76.92%), liver (58.33%), heart (50%), brain (42.30%), and kidney (23.07%) tissues. Serology performed through indirect hemagglutination showed reactivity in 85.7% of the animals, all belonging to Sapajus sp., while the three primates that did not show reactivity (14.3%) belonged to Alouatta sp