Host range and susceptibility to Toxoplasma gondii infection in captive neotropical and Old‐world primates

Abstract

BackgroundToxoplasmosis is an important disease affecting captive non‐human primates. The goal of this study was to assess the seroprevalence and pathological findings of toxoplasmosis in different species of captive primates.MethodsSix captive neotropical primates died naturally due to Toxoplasma gondii infection and were necropsied. Tissue samples were evaluated by histopathology and immunohistochemistry. Serum samples from 57 captive neotropical and Old‐world primates housed at the Belo Horizonte zoological garden were analyzed by indirect fluorescent antibody test (IFAT), enzyme‐linked immunosorbent assay (ELISA), and indirect hemagglutination assay (IHA).ResultsNeotropical primates had lesions compatible with toxoplasmosis with immunolabeled intralesional T gondii. All Old‐World primates (10/10), but only three neotropical primates (3/47), all belonging to the Sapajus apella species (3/6), were serologically positive.ConclusionsOur results suggest a higher susceptibility of neotropical primates to toxoplasmosis. However, this study also supports the hypothesis that Sapajus apella may be naturally resistant.

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

“…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. This finding further supports the difference in susceptibility to toxoplasmosis between capuchins and other neotropical primate species that has been previously demonstrated 10,18 . Unfortunately, biological samples from the cat and capuchins were not available for analysis throughout the course of the outbreak.…”

“…1 through 7; tm: titi monkey ( Callicebus spp.) from a previously diagnosed unrelated case of toxoplasmosis 18 ; NA, not available.…”

“…These findings further support the notion that there are marked differences in natural resistance against T. gondii among different species of non‐human primates. Indeed, a recent study demonstrated very low seroprevalence of toxoplasmosis and very high lethality rate in several neotropical non‐human primate species, with the exception of capuchins ( S. apella ), whereas Old World primates tend to have high seroprevalence and absence of lethality due to T. gondii infection 18 . Hypotheses to explain these differences include possible natural resistance or behavioral features since Old World primates remain on the soil most of the time, while neotropical primates have mostly arboreal behavior and, consequently, rare contact with soil and feline feces 10,18 .…”

“…Samples of the liver, spleen, lungs, and brain from a captive titi monkey ( Callicebus sp.) from a completely different area and previously diagnosed with toxoplasmosis 18 were also submitted to PCR analyses as external controls to the outbreak.…”

“…Outbreaks of toxoplasmosis affecting neotropical primates have been previously reported 4,10,12,16,17 . It is known that neotropical primates are more susceptible to toxoplasmosis than Old World primates 15,18 …”