Investigação molecular da infecção por mayaro vírus em primatas não humanos no estado de Minas Gerais (2017-2020) e otimização de teste de neutralização viral alternativo para investigação da infecção por mayaro vírus.

Abstract

Mayaro virus (MAYV; genus Alphavirus, family Togaviridae) is the etiologic agent causing Mayaro fever, a disease characterized by clinical signs such as fever, joint pain, and exanthema. MAYV is transmitted to non-human primates (NHP) by the bite of female mosquitoes of the genus Haemagogus spp. which, in turn, can also transmit the virus to humans, who become accidental hosts in a phenomenon known as spillover. In Brazil, MAYV and yellow fever virus (YFV), which causes yellow fever (YF), share vectors and hosts, besides presenting overlapping areas where they circulate. In this context, this work aims to investigate the presence of MAYV genome in samples of NHP collected during recent outbreaks of yellow fever in the state of Minas Gerais and to optimize a viral neutralization assay (PRNT) using liver samples from experimental animals as a serum substitute to investigate MAYV infection. For the molecular investigation, 732 liver samples from free-living NHP were tested by polymerase chain reaction (PCR) for the detection of a MAYV genome region. For the standardization of the neutralization test, liver samples from experimental animals were used in place of serum in an adapted PRNT protocol. The presence of the MAYV genome could not be detected in NHP liver samples. Neutralization was observed in samples from experimental animals, which was not observed to the same extent in uninfected animals. The viral neutralization technique adapted in this work showed promise for use in the investigation of the presence of neutralizing antibodies in liver samples obtained from carcasses and may be of great value for epidemiological surveillance efforts of arboviruses in the country. The nondetection of MAYV genome in liver samples from PNH does not exclude the possibility of circulation, or even future introduction of the virus in MG, requiring continued surveillance work to monitor any outbreaks.