Study of Arboviruses in Philander opossum, Didelphis marsupialis and Nectomys rattus captured from forest fragments in the municipality of Belém, Pará, Brazil

ABSTRACT: Arboviruses are viruses that maintain their life cycle in the wild and are transmitted to vertebrate hosts by hematophagous diptera. They are zoonotic and can establish an enzootic cycle in the urban areas; in humans, the infection can manifest from being encephalitogenic to hemorrhagic. This study aimed to report the occurrence of arboviruses in mammals of the order Didelphimorphia and Rodentia, captured from the Amazon. Serum samples were subjected to hemagglutination inhibition test using a viral panel of 19 species of arboviruses that are known to occur in the Amazon. Altogether, 14 wild mammals, 12 of Philander opossum, 1 of Didelphis marsupialis, and 1 of Nectomys rattus were captured. Eight of these were reported to be seropositive for arboviruses (57.14%) with monotypic seroprevalence for the Eastern Equine Encephalitis Virus (n=1), the Ilheus Virus (n=2), and the Catu virus (n=4); 4 heterotypic responses were observed for Flavivirus and Orthobunyavirus. In conclusion, several arbovirus species are in active circulation and maintenance, exhibiting enzootic characteristics in the wild mammals of the Amazon region; these animals prove to be potential hosts in the transmission of diseases to humans.

摘要：虫媒病毒（Arbovirus）是一类在野外维持自身生命周期，并通过吸血双翅目昆虫传播给脊椎动物宿主的病毒。该类病毒为人畜共患病原体，可在城市区域建立兽疫循环；在人体中，其感染可表现为从致脑炎到出血性等多种临床症状。本研究旨在报道捕获自亚马逊地区的负鼠目（Didelphimorphia）和啮齿目（Rodentia）哺乳动物中的虫媒病毒感染情况。研究人员采用由19种已知在亚马逊地区流行的虫媒病毒组成的病毒检测组，对血清样本开展血凝抑制试验（hemagglutination inhibition test）。本次共捕获14只野生哺乳动物，包括12只菲氏负鼠（Philander opossum）、1只大负鼠（Didelphis marsupialis）以及1只稻大鼠（Nectomys rattus）。其中8份样本呈虫媒病毒血清学阳性（阳性率为57.14%），单型别血清阳性情况为：东部马脑炎病毒（Eastern Equine Encephalitis Virus）1例、伊胡斯病毒（Ilheus Virus）2例、卡图病毒（Catu virus）4例；另有4份样本呈现黄病毒属（Flavivirus）与正布尼亚病毒属（Orthobunyavirus）的异型血清学反应。研究结论表明，亚马逊地区的野生哺乳动物体内存在多种正在活跃循环与维持的虫媒病毒物种，呈现出兽疫流行特征；这类动物可作为潜在宿主，参与虫媒病毒向人类的疾病传播过程。