The sylvatic cycle of rabies, caused by the Rabies lyssavirus (RABV), is maintained in the American Continent by aerial and terrestrial wild mammals. In this study, we combined passive surveillance of rescued wild animals with active serological surveillance in targeting areas at Rio Grande do Sul State and Santa Catarina State, south of Brazil, where bites of humans by wild animals have been reported. Circulation of RABV in Brazilian bats has been extensively demonstrated; however, the observation of such infections in unvaccinated terrestrial mammals is restricted to some regions of the Brazilian territory. The occurrence of rabies infection in unvaccinated animals has been identified by the detection of RABV antigens in brain tissues of dead animals or anti-rabies antibodies in live animals. Such strategies allow the surveillance of rabies and the assessment of spillover risks from infected animals to humans. Our aim included the identification of species of wild mammals that are involved in the sylvatic cycle of rabies virus in Southern Brazil and to assess the risk of rabies infection in patients bitten by wild animals in the state. To assess the anti-rabies seropositivity, sera were submitted to the Rapid Fluorescent Focus Inhibition Test (RFFIT). Among the 100 mammals tested, five animals were seropositive (5%) including three (one primate and two wild canids) with rabies virus neutralizing antibodies titres >0.5 IU/ml. Our results highlight the exposure to RABV of both primates and wild canids in Southern Brazil and suggest the occurrence of RABV exposure without the development of further symptoms. Further research should clarify the dynamics of rabies in wild canids and whether primates are accidental hosts or reservoirs for RABV at this region.

中文翻译：

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巴西南部野生哺乳动物的狂犬病监测。

由狂犬病狂犬病病毒（RABV）引起的狂犬病的狂犬病周期在美洲大陆由空中和陆生野生哺乳动物维持。在这项研究中，我们在巴西南部的南里奥格兰德州和圣卡塔琳娜州的目标地区结合了对获救野生动物的被动监视和主动血清学监视，据报道，那里被野生动物叮咬。已经广泛证明了RABV在巴西蝙蝠中的传播。但是，在未接种疫苗的陆生哺乳动物中观察到此类感染仅限于巴西领土的某些地区。通过检测死动物脑组织中的RABV抗原或活体动物中的抗狂犬病抗体，可以确定未接种疫苗的动物中狂犬病感染的发生。这种策略可以监视狂犬病，并评估从被感染的动物到人类的溢出风险。我们的目标包括鉴定与巴西南部狂犬病病毒的狂犬病周期有关的野生哺乳动物物种，并评估该州被野生动物咬伤的患者狂犬病感染的风险。为了评估抗狂犬病的血清阳性，将血清进行了快速荧光聚焦抑制试验（RFFIT）。在测试的100只哺乳动物中，有5只动物具有血清阳性（5％），其中包括3只（灵长类动物和2只野生犬科动物），狂犬病毒中和抗体滴度> 0.5 IU / ml。我们的研究结果突显了巴西南部灵长类动物和野生犬类动物均暴露于RABV，并表明RABV暴露的发生没有进一步症状的发展。