Case report: Urbanized non-human primates as sentinels for human zoonotic diseases: a case of acute fatal toxoplasmosis in a free-ranging marmoset in coinfection with yellow fever virus.

Free-ranging non-human primates (NHP) can live in anthropized areas or urban environments in close contact with human populations. This condition can enable the emergence and transmission of high-impact zoonotic pathogens. For the first time, we detected a coinfection of the yellow fever (YF) virus with Toxoplasma gondii in a free-ranging NHP in a highly urbanized area of a metropolis in Brazil. Specifically, we observed this coinfection in a black-tufted marmoset found dead and taken for a necropsy by the local health surveillance service. After conducting an epidemiological investigation, characterizing the pathological features, and performing molecular assays, we confirmed that the marmoset developed an acute fatal infection caused by T. gondii in coinfection with a new YF virus South American-1 sub-lineage. As a result, we have raised concerns about the public health implications of these findings and discussed the importance of diagnosis and surveillance of zoonotic agents in urbanized NHPs. As competent hosts of zoonotic diseases such as YF and environmental sentinels for toxoplasmosis, NHPs play a crucial role in the One Health framework to predict and prevent the emergence of dangerous human pathogens.

Hepato-pathological hallmarks for the surveillance of Yellow Fever in South American non-human primates.

The early detection and diagnosis of deaths in free-ranging non-human primates (NHPs) are key points for the surveillance of Yellow Fever (YF) in Brazil. The histopathological identification of infectious diseases remains very useful and reliable in the screening and detection of emerging zoonotic diseases such as YF. We surveyed data records and liver slides stained with hematoxylin and eosin from the Epizootics Surveillance Network to control YF, Ministry of Health of Brazil, to evaluate histopathological hallmarks for the diagnosis of the YF virus infection. We selected natural fatal cases in NHPs from the genera Alouatta spp., Callithrix spp., and Sapajus spp. with a positive immunohistochemical assay for YF in liver samples. Our findings showed the full-spectrum YF-associated hepatic lesions in all NHPs, but some histopathological findings differed in the distribution and intensity between the three genera. In our study, South American NHPs showed significant differences in the YF-associated hepatic histopathological features compared to fatal cases reported in humans.

Electrocutions in free-living black-tufted marmosets (Callithrix penicillata) in anthropogenic environments in the Federal District and surrounding areas, Brazil.

Shrinking natural habitats exposes some non-human primates to the risk of accidents associated with electrical transmission lines. We examined dead marmosets (Callithrix penicillata) collected in the region from January 2015 to April 2018 to determine the animals' cause of death and for electrocuted animals we examined the locations the animals had died as well as the configuration of the power lines at these sites. We also recorded the sex of the animal, the body region affected, and characteristics of the injuries. We diagnosed electrocutions in 11% (n = 34) of the marmosets studied. Most of the affected animals were male (n = 22) with single or double sites of injury on the limbs. Animals were injured in urban (n = 26) and peri-urban (n = 8) areas on lower-voltage alternate current lines, and we detected no seasonality or hotspots of electrocution. Our findings suggest that movement along transmission lines composed of bundled conductors is a major factor in electrocutions of marmosets in the Federal District and surrounding areas. The planning of electrical power grid infrastructure should consider arboreal primates to prevent electrocutions.