Zika Virus Surveillance at the Human–Animal Interface in West-Central Brazil, 2017–2018
Authors: Pauvolid-Corrêa Alex , Gonçalves Dias Helver , Marina Siqueira Maia Laura , Porfírio Grasiela , Oliveira Morgado Thais , Sabino-Santos Gilberto , Helena Santa Rita Paula , Teixeira Gomes Barreto Wanessa , Carvalho de Macedo Gabriel , Marinho Torres Jaire , Arruda Gimenes Nantes Wesley , Martins Santos Filipe , Oliveira de Assis William , Castro Rucco Andreza , Mamoru dos Santos Yui Rafael , Bosco Vilela Campos João , Rodrigues Leandro e Silva Renato , da Silva Ferreira Raquel , Aparecido da Silva Neves Nilvanei , Charlles de Souza Costa Michell , Ramos Martins Leticia , Marques de Souza Emerson , dos Santos Carvalho Michellen , Gonçalves Lima Marina , de Cássia Gonçalves Alves Fernanda , Humberto Guimarães Riquelme-Junior Luiz , Luiz Batista Figueiró Luan , Fernandes Gomes de Santana Matheus , Gustavo Rodrigues Oliveira Santos Luiz , Serra Medeiros Samara , Lopes Seino Larissa , Hime Miranda Emily , Henrique Rezende Linhares José , de Oliveira Santos Vanessa , Almeida da Silva Stephanie , Araújo Lúcio Kelly , Silva Gomes Viviane , de Araújo Oliveira Alexandre , dos Santos Silva Julia , de Almeida Marques William , Schafer Marques Marcio , Junior França de Barros José , Campos Letícia , Couto-Lima Dinair , Coutinho Netto Claudia , Strüssmann Christine , Panella Nicholas , Hannon Emily , Cristina de Macedo Barbara , Ramos de Almeida Júlia , Ramos Ribeiro Karen , Carolina Barros de Castro Maria , Pratta Campos Larissa , Paula Rosa dos Santos Ana , Marino de Souza Isabelle , de Assis Bianchini Mateus , Helena Ramiro Correa Sandra , Ordones Baptista Luz Renato , dos Santos Vieira Ananda , Maria de Oliveira Pinto Luzia , Azeredo Elzinandes , Tadeu Moraes Figueiredo Luiz , Augusto Fonseca Alencar Jeronimo , Maria Barbosa de Lima Sheila , Miraglia Herrera Heitor , Dezengrini Shlessarenko Renata , Barreto dos Santos Flavia , Maria Bispo de Filippis Ana , Salyer Stephanie , Montgomery Joel , Komar Nicholas 
Published: December 2019

Zika virus (ZIKV) was first discovered in 1947 in Uganda but was not considered a public health threat until 2007 when it found to be the source of epidemic activity in Asia. Epidemic activity spread to Brazil in 2014 and continued to spread throughout the tropical and subtropical regions of the Americas. Despite ZIKV being zoonotic in origin, information about transmission, or even exposure of non-human vertebrates and mosquitoes to ZIKV in the Americas, is lacking. Accordingly, from February 2017 to March 2018, we sought evidence of sylvatic ZIKV transmission by sampling whole blood from approximately 2000 domestic and wild vertebrates of over 100 species in West-Central Brazil within the active human ZIKV transmission area. In addition, we collected over 24,300 mosquitoes of at least 17 genera and 62 species. We screened whole blood samples and mosquito pools for ZIKV RNA using pan-flavivirus primers in a real-time reverse-transcription polymerase chain reaction (RT-PCR) in a SYBR Green platform. Positives were confirmed using ZIKV-specific envelope gene real-time RT-PCR and nucleotide sequencing. Of the 2068 vertebrates tested, none were ZIKV positive. Of the 23,315 non-engorged mosquitoes consolidated into 1503 pools tested, 22 (1.5%) with full data available showed some degree of homology to insect-specific flaviviruses. To identify previous exposure to ZIKV, 1498 plasma samples representing 62 species of domestic and sylvatic vertebrates were tested for ZIKV-neutralizing antibodies by plaque reduction neutralization test (PRNT90). From these, 23 (1.5%) of seven species were seropositive for ZIKV and negative for dengue virus serotype 2, yellow fever virus, and West Nile virus, suggesting potential monotypic reaction for ZIKV. Results presented here suggest no active transmission of ZIKV in non-human vertebrate populations or in alternative vector candidates, but suggest that vertebrates around human populations have indeed been exposed to ZIKV in West-Central Brazil.