Sylvatic transmission of arboviruses among Bornean orangutans

Wild populations of nonhuman primates live in regions of sylvatic arbovirus transmission. To assess the status of arbovirus transmission in Bornean fo rests and the susceptibility of wild orangutans to arboviral infection, blo od samples of wild orangutans. semi-captive orangutans, and humans were exa mined. Samples were tested by plaque reduction neutralization test for anti bodies to viruses representing three families (Flaviviridae, Alphaviridae, and Bunyaviridae), including dengue-2, Japanese encephalitis, Zika, Langat, Tembusu, Sindbis, Chikungunya, and Batai viruses. Both wild and semi-capti ve orangutan groups as well as local human populations showed serologic evi dence of arbovirus infection. The presence of neutralizing antibodies among wild orangutans strongly suggests the existence of sylvatic cycles for den gue, Japanese encephalitis, and sindbis viruses in North Borneo. The presen t study demonstrates that orangutans are susceptible to arboviral infection s in the wild, although the impact of arboviral infections on this endanger ed ape remain unknown.