Detection of Yellow Fever Virus in Sylvatic Mosquitoes during Disease Outbreaks of 2017⁻2018 in Minas Gerais State, Brazil.

Guilherme Garcia Pinheiro,Maria Angélica De Oliveira,José Dilermando Andrade Filho,Luciano Andrade Moreira,Marcele Neves Rocha

doi:10.3390/insects10050136

Abstract

Brazil has experienced several arbovirus outbreaks in recent years, among which yellow fever stands out. The state of Minas Gerais faced outbreaks of sylvatic yellow fever in 2017 and 2018, with 1002 confirmed cases and 340 deaths. This work presents the results of survey efforts to detect the yellow fever virus in mosquitoes from two conservation areas in the metropolitan region of Belo Horizonte, Brazil. A total of 867 mosquitoes of 20 species were collected between September 2017 and May 2018, the most abundant being Psorophora (Janthinosoma) ferox (von Humboldt, 1819) (31.3%), Limatus durhamii Theobald, 1901 (19.1%) and Haemagogus (Haemagogus) janthinomys Dyar, 1921 (18.2%). Total RNA was extracted from the mosquitoes for real-time PCR analysis for yellow fever, chikungunya, mayaro, Zika and dengue viruses. The yellow fever infection rate was 8.2% for Hg. janthinomys (13 mosquitoes), which is the main vector of sylvatic yellow fever in Brazil. In addition to surveying the mosquito fauna of these conservation units, this work demonstrates the importance of monitoring the circulation of viruses near large urban centers.

Highlights

Yellow fever (YF) is a severe acute disease with high lethality (20–50% among symptomatic cases) [1] and is caused by yellow fever virus (YFV), an arbovirus of the family Flaviviridae
Scientists have warned public health authorities that once the virus started circulating near large metropolitan areas, the risk of re-emergence of YF would increase
Recent studies have revealed that cases of sylvatic YF and infected mosquitoes are being reported closer to large urban areas, such Belo Horizonte and São Paulo

Summary

Introduction

Yellow fever (YF) is a severe acute disease with high lethality (20–50% among symptomatic cases) [1] and is caused by yellow fever virus (YFV), an arbovirus of the family Flaviviridae. The virus is exclusively transmitted to its hosts through bites of female mosquitos of some species of the family. The disease presents two distinct transmission cycles: the sylvatic cycle and the urban cycle. These cycles share similarities regarding their etiology and disease evolution, they have different vectors and hosts. The main vector for the sylvatic cycle in the Americas is Haemagogus (Haemagogus) janthinomys Dyar, 1921, which is widely distributed in Brazil from the state of Santa. The main hosts of the virus are non-human primates (NHP’s), such as howler monkeys (Alouatta sp), while humans become infected accidentally

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