RESUMEN
BACKGROUND: Free-ranging non-human primates (NHPs) can host a variety of pathogenic microorganisms, such as arboviruses, which include the yellow fever virus (YFV). This study aimed to detect the circulation of YF and other arboviruses in three wild Alouatta caraya populations in forests in southern Brazil. METHODS: We collected 40 blood and serum samples from 26 monkeys captured/recaptured up to four times from 2014 to 2016, searching for evidence of arboviruses by virus isolation, PCR, and neutralization tests. RESULTS: Viral isolation and genome detection were negative; however, we detected neutralizing antibodies against the Saint Louis, Ilhéus, and Icoaraci viruses in three NHPs. CONCLUSIONS: Saint Louis Encephalitis, Ilhéus, and Icoaraci viruses circulated recently in the region. Future studies should investigate the role of NHPs, other vertebrate hosts and wild vectors in the region's arbovirus circulation and the potential risks of the arboviruses to wildlife, domestic animals, and humans.
Asunto(s)
Alouatta caraya , Encefalitis de San Luis/veterinaria , Infecciones por Flavivirus/veterinaria , Enfermedades de los Monos/epidemiología , Fiebre del Valle del Rift/epidemiología , Animales , Anticuerpos Antivirales/sangre , Brasil/epidemiología , Virus de la Encefalitis de San Luis/aislamiento & purificación , Encefalitis de San Luis/epidemiología , Encefalitis de San Luis/virología , Flavivirus/aislamiento & purificación , Infecciones por Flavivirus/epidemiología , Infecciones por Flavivirus/virología , Fiebre del Valle del Rift/virología , Virus de la Fiebre del Valle del Rift/aislamiento & purificaciónRESUMEN
The natural transmission cycle of Yellow Fever (YF) involves tree hole breeding mosquitoes and a wide array of nonhuman primates (NHP), including monkeys and apes. Some Neotropical monkeys (howler monkeys, genus Alouatta) develop fatal YF virus (YFV) infections similar to those reported in humans, even with minimum exposure to the infection. Epizootics in wild primates may be indicating YFV circulation, and the surveillance of such outbreaks in wildlife is an important tool to help prevent human infection. In 2001, surveillance activities successfully identified YF-related death in a black-and-gold howler monkey (Alouatta caraya), Rio Grande do Sul State (RGS) in southern Brazil, and the YFV was isolated from a species of forest-dwelling mosquito (Haemagogus leucocelaenus). These findings led the State Secretariat of Health to initiate a monitoring program for YF and other 18 arboviral infections in Alouatta monkeys. The monitoring program included monkey captures, reporting of monkey casualties by municipalities, and subsequent investigations. If monkey carcasses were found in forests, samples were collected in a standardized manner and this practice resulted in increased reporting of outbreaks. In October 2008, a single howler monkey in a northwestern RGS municipality was confirmed to have died from YF. From October 2008 to June 2009, 2,013 monkey deaths were reported (830 A. caraya and 1,183 A. guariba clamitans). Viruses isolation in blood, viscera, and/or immunohistochemistry led to the detection of YF in 204 of 297 (69%) (154 A. g. clamitans and 50 A. caraya) dead Alouatta monkeys tested. The number of municipalities with confirmed YFV circulation in howlers increased from 2 to 67 and 21 confirmed human cases occurred. This surveillance system was successful in identifying the largest YF outbreak affecting wild NHP ever recorded.