Yellow fever transmission in non-human primates, Bahia, Northeastern Brazil.

Jaqueline Góes De Jesus ,Gabriel Muricy Cunha,Jananci Xavier Gomes Cerqueira,Jeane Magnavita Da Fonseca Cerqueira,Zuinara Pereira Gusmão Maia,Leandro Abade,Felicidade Mota Pereira,Roberto Fonseca Dos Santos,Allison Fabri,Eloisa Bahia Santana,Joilson Xavier,Leandro Ferraz Oliveira Santos,Maricelia Lima Maia,Sintia Sacramento Cerqueira Torquato,Tiago Gräf,Rosemary Sarmento Oitiçica Dourado,André Luiz De Abreu,Mirza De Carvalho Santana Cordeiro,Vagner Fonseca,Maria Angélica Mares-Guia,Luciana Reboredo De Oliveira Da Silva,Rodrigo Fabiano Do Carmo Said,Nuno Rodrigues Faria,Ademilson Brás Alves,Marta Giovanetti,Adeilde Do Socorro Guedes,Pedro Macedo Da Silva Filho,Neuza Santos De Jesus Silva,Arabela Leal E Silva De Mello,Julien Thézé ,Carlos Frederico Campelo De Albuquerque ,Júlio Croda ,Ana María Bispo De Filippis ,Alessandro Romano ,Luiz Carlos Júnior Alcântara

doi:10.1371/journal.pntd.0008405

Abstract

Yellow fever virus (YFV) causes a clinical syndrome of acute hemorrhagic hepatitis. YFV transmission involves non-human primates (NHP), mosquitoes and humans. By late 2016, Brazil experienced the largest YFV outbreak of the last 100 years, with 2050 human confirmed cases, with 681 cases ending in death and 764 confirmed epizootic cases in NHP. Among affected areas, Bahia state in Northeastern was the only region with no autochthonous human cases. By using next generation sequence approach, we investigated the molecular epidemiology of YFV in NHP in Bahia and discuss what factors might have prevented human cases. We investigated 47 YFV positive tissue samples from NHP cases to generate 8 novel YFV genomes. ML phylogenetic tree reconstructions and automated subtyping tools placed the newly generated genomes within the South American genotype I (SA I). Our analysis revealed that the YFV genomes from Bahia formed two distinct well-supported phylogenetic clusters that emerged most likely of an introduction from Minas Gerais and Espírito Santo states. Vegetation coverage analysis performed shows predominantly low to medium vegetation coverage in Bahia state. Together, our findings support the hypothesis of two independent YFV SA-I introductions. We also highlighted the effectiveness of the actions taken by epidemiological surveillance team of the state to prevented human cases.

Highlights

Yellow fever virus (YFV) is an enveloped, single-stranded RNA virus, with an approximately 11,000 base pair genome, belonging to the Flaviviridae family
Our findings support the hypothesis of two independent YFV SA-I introductions
In the period between July 2018 and June 2019, 268 non-human primates (NHP) epizootic suspected cases have been reported in 61 municipalities in Bahia state, none was confirmed for YFV infection [16]

Summary

Introduction

Yellow fever virus (YFV) is an enveloped, single-stranded RNA virus, with an approximately 11,000 base pair genome, belonging to the Flaviviridae family. The urban (or domestic) transmission cycle involves viremic humans who were infected by the virus in the forest regions or through the intermediate cycle, which returns to an urban area. Between July 2017 and June 2018, the epidemiological surveillance division reported 58 human YF suspected cases in Bahia, from which laboratory tests confirmed all cases were imported, with no autochthonous confirmed cases in the state. Considering the seasonality of the virus transmission in the country and the release of epidemiological data reports, from July 2017 to June 2018, 846 NHP epizootic cases were reported, and none was confirmed by laboratory tests. In the period between July 2018 and June 2019, 268 NHP epizootic suspected cases have been reported in 61 municipalities in Bahia state, none was confirmed for YFV infection [16]

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