**6. Dengue virus jungle cycle and reverse zoonosis**

DENV can circulate in jungle cycles where virus can remain in place using *nonhuman primates* (NHP) as reservoirs or viruses transmitted in an urban cycle can infect non-human primates ('spillback' or 'reverse zoonosis') [12]. The urban and jungle cycles are shown to exist in Asia and Africa, in countries such as Malaysia, Senegal, the Philippines where DENV would be identified by a virus isolation from species such as *Presbytis obscura*, *Erythrocebus patas,* and *Macaca fascicularis* respectively [32]. Studies conducted in South East Asia reported antibodies in nonhuman primates in Indonesia, the Philippines, Cambodia, Vietnam and Malaysia. DENV viral isolation or identification by RT-PCR in NHP has not been reported in Americas but wild caught patas monkeys (*Erythrocebus patas*) and rhesus macaques (*Macaca mulatta*) showing antibodies against DENV by PRNT were reported in a study carried out between 2010 and 2012 in Puerto Rico [32]. As no evidences of DENV jungle cycle in America were shown, it is believed that these results may represent a spillback infection and non-human primates would get the infection of urban cycles presented in the population. In Argentina 2020, antibodies against DENV-1 y DENV-3 in howler monkeys (*Alouatta caraya*) were found; and in Brazil between 2006 and 2014, low antibodies against DENV in free-living golden headed lion tamarins (*Leontopithecus chrysomelas*) were found [32]. These cases were also assumed to result from spillback infection. A study in Thailand in 2008–2009 identified 6 DENV positive-dogs by RT-PCR and/or viral isolation in urban areas,

2 were DENV-2 positive and 4 were DENV-3 positive in a rubber plantation area [33]. It is necessary to continue with this type of studies in these animals in order to develop a viremia high enough to infect mosquitoes. More than 200 viruses from 27 families, including *flaviviridae*, was isolated or detected in bats and several studies have shown DENV nucleic acids and/or antibodies present in Neotropical wildlife. A study in Costa Rica suggest that bats are infected accidentally by DENV because the RNA quantification in blood was low below the minimum infectious dose of mosquito that is needed to maintain the transmission cycle for the virus. Thus, they were considered as dead-end hosts for dengue virus [34].
