Fatal toxoplasmosis in a southern muriqui (Brachyteles arachnoides) from São Paulo state, Brazil: Pathological, immunohistochemical, and molecular characterization

Abstract

We report the pathological, immunohistochemical, and molecular features of fatal acute systemic toxoplasmosis in an adult, female, free-living southern muriqui (Brachyteles arachnoides) from São Paulo state, Brazil. PCR-RFLP genotyping analysis identified the #21 genotype of Toxoplasma gondii. This represents the first report of acute toxoplasmosis involving this genotype in humans and animals.

Genotyping of Toxoplasma gondii in a lethal toxoplasmosis outbreak affecting captive howler monkeys (Alouatta sp.)

“…Necrotizing hepatitis, encephalitis, and lymphadenitis, with intralesional cysts with bradyzoites and extracellular tachyzoites were the most severe lesions observed in howler monkeys in this outbreak. Previous reports described similar necrotizing lesions in the liver 4,10,12,22 and lymph nodes 4,10,12,16,22 ). Six out of seven howler monkeys developed pulmonary edema, and three howler monkeys had intra‐alveolar deposition of fibrin, with fibrinous membranes on the alveolar epithelia surface.…”

“…All howler monkeys in this outbreak had moderate to severe hepatic lipidosis. Previous reports described hepatic lipidosis in neotropical primates with hepatic lesions caused by T. gondii 18,22 . However, there is no clear cause and effect relationship between lipidosis and T. gondii infection.…”

“…Therefore, we presume that the recently introduced cat may have been the source of infection for these howler monkeys. Domestic and feral cats are a known source of infection to humans and non‐human primates, and previous toxoplasmosis cases have described contact with cats before the development of the disease 22 . Interestingly, capuchins that also had contact and often played with the same cat and were fed with vegetables from the same garden neither develop clinical signs nor died.…”

“…Although T. gondii cysts and tachyzoites were observed in the liver, brain, spleen, lymph node, heart, and bone marrow in these howler monkeys, the pathogen may be difficult to be identified in HE‐stained sections, especially in the presence of lesions. Therefore, immunohistochemistry may be useful for detecting T. gondii cysts and tachyzoites and it has been previously used for diagnosing toxoplasmosis 10,12,16,22 …”

Pathology and epidemiology of fatal toxoplasmosis in free-ranging marmosets (Callithrix spp.) from the Brazilian atlantic forest

“…Neotropical primates (New World Primates; NWP) are highly susceptible to toxoplasmosis [1][2][3]. In captive NWP, toxoplasmosis is characterized by a hyperacute to acute, systemic disease with difficult treatment approach, that evolves quickly to death, being sometimes associated with outbreaks with high lethality [1][2][3][4][5][6][7]. There are differences in susceptibility between NWP species, with capuchins being considered more resistant than other neotropical species [2,6].…”