Haemagogus leucocelaenus and Haemagogus janthinomys are the primary vectors in the major yellow fever outbreak in Brazil, 2016–2018

Filipe Vieira Santos De Abreu,Ieda Pereira Ribeiro,Anielly Ferreira-De-Brito,Rafaella Moraes De Miranda,Iule De Souza Bonelly,Maycon Sebastião Alberto Santos Neves,Taissa Pereira Dos Santos,Marcelo Quintela Gomes,Roberta Gomes Carvalho,Rodrigo Fabiano Do Carmo Said,Roberto Da Costa Laperrière,Mário Sérgio Ribeiro ,Alessandro Romano ,Anna‐Bella Failloux ,Maria Ignez Lima Bersot ,Myrna C Bonaldo ,José Luís Da Silva ,Mariela Martínez Goméz ,Eduardo Oyama Lins Fonseca,Alexandre Araújo Cunha Dos Santos ,Márcia Gonçalves De Castro ,Aloísio Falqueto,Christophe Paupy,Sara Moutailler,Monique De Albuquerque Motta,Ricardo Lourenço‐De‐Oliveira

doi:10.1080/22221751.2019.1568180

Abstract

ABSTRACT The yellow fever virus (YFV) caused a severe outbreak in Brazil in 2016–2018 that rapidly spread across the Atlantic Forest in its most populated region without viral circulation for almost 80 years. A comprehensive entomological survey combining analysis of distribution, abundance and YFV natural infection in mosquitoes captured before and during the outbreak was conducted in 44 municipalities of five Brazilian states. In total, 17,662 mosquitoes of 89 species were collected. Before evidence of virus circulation, mosquitoes were tested negative but traditional vectors were alarmingly detected in 82% of municipalities, revealing high receptivity to sylvatic transmission. During the outbreak, five species were found positive in 42% of municipalities. Haemagogus janthinomys and Hg. leucocelaenus are considered the primary vectors due to their large distribution combined with high abundance and natural infection rates, concurring together for the rapid spread and severity of this outbreak. Aedes taeniorhynchus was found infected for the first time, but like Sabethes chloropterus and Aedes scapularis, it appears to have a potential local or secondary role because of their low abundance, distribution and infection rates. There was no evidence of YFV transmission by Aedes albopictus and Aedes aegypti, although the former was the most widespread species across affected municipalities, presenting an important overlap between the niches of the sylvatic vectors and the anthropic ones. The definition of receptive areas, expansion of vaccination in the most affected age group and exposed populations and the adoption of universal vaccination to the entire Brazilian population need to be urgently implemented.

Highlights

Yellow fever (YF) is a viral disease that decimated populations and harmed commercial routes in the Americas in the nineteenth century and continues to induce a heavy public health burden by annually causing thousands of cases and deaths in Africa and South America despite the existence of effective vaccines [1,2]
Collections before the yellow fever outbreak: During this period, 5,341 mosquitoes were collected in 28 municipalities in Rio de Janeiro (RJ) and in two bordering states (SP and Minas Gerais state (MG))
Regarding other traditional yellow fever virus (YFV) vectors, Hg. janthinomys and Sabethes chloropterus were detected in 39.2% and 10.7% of the municipalities surveyed before virus circulation, with a relative abundance of 1.6% and 0.21%, respectively (Figures 1 and 2, Table 1 and S1)

Summary

Introduction

Yellow fever (YF) is a viral disease that decimated populations and harmed commercial routes in the Americas in the nineteenth century and continues to induce a heavy public health burden by annually causing thousands of cases and deaths in Africa and South America despite the existence of effective vaccines [1,2]. The etiological agent of this disease is the yellow fever virus (YFV), which has originated in Africa and spread to the Americas and the Caribbean probably during the seventeenth—nineteenth centuries. The discovery that YFV is transmitted by the bite of the domestic mosquito Aedes (Stegomyia) aegypti revolutionized the understanding of its epidemiology and guided control and protection measures for urban human populations early in the twentieth century [3,4,5]

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Conclusion