Natural Infection and Vertical Transmission of Zika Virus in Sylvatic Mosquitoes Aedes albopictus and Haemagogus leucocelaenus from Rio de Janeiro, Brazil.

Jeronimo Alencar,Anthony Érico Guimarães,Helena Keiko Toma,Cecilia Ferreira De Mello,Sergio Lisboa Machado,Shayenne Olsson Freitas Silva,Carlos Brisola Marcondes,Amanda Queiroz Bastos

doi:10.3390/tropicalmed6020099

Abstract

Zika virus (ZIKV) was recently introduced into the Western Hemisphere, where it is suspected to be transmitted mainly by Aedes aegypti in urban environments. ZIKV represents a public health problem as it has been implicated in congenital microcephaly in South America since 2015. Reports of ZIKV transmission in forested areas of Africa raises the possibility of its dispersal to non-human-modified environments in South America, where it is now endemic. The current study aimed to detect arboviruses in mosquitoes collected from areas with low human interference in Rio de Janeiro, Brazil. Using a sensitive pan-flavivirus RT-PCR, designed to detect the NS5 region, pools of Ae. albopictus and Haemagogus leucocelaenus, were positive for both ZIKV and yellow fever (YFV). Virus RNA was detected in pools of adult males and females reared from field-collected eggs. Findings presented here suggest natural vertical transmission and infection of ZIKV in Hg. leucocelaenus and Ae. albopitcus in Brazil.

Highlights

The family Flaviviridae contains four genera, including Flavivirus, a genus that contains over 50 viruses, with 13 being already reported in Brazil
Among the most important flaviviruses circulating in Brazil are yellow fever (YF), dengue (DENV), Zika (ZIKV) and West Nile viruses
Six pools from two species were positive for flavivirus by RT-polymerase chain reaction (PCR) and submitted to nucleotide sequencing

Summary

Introduction

The family Flaviviridae contains four genera, including Flavivirus, a genus that contains over 50 viruses, with 13 being already reported in Brazil. Among the most important flaviviruses circulating in Brazil are yellow fever (YF), dengue (DENV), Zika (ZIKV) and West Nile viruses. Yellow fever has been a major health problem since the first epidemic occurred in Recife in 1685 [1]. This disease was essentially eliminated from urban areas by the early 20th century; in the 1920s, sylvatic transmission was detected in Colombian forest areas. Sylvatic transmission among non-human primates by forest mosquitoes was first identified and verified in Brazil in the Chanaan Valley, located in the state of Espirito Santo, southeast Brazil [2]. ZIKV, first identified in a forest in Uganda, has recently spread to Asia and the Pacific islands, and later to the Americas, where it caused explosive outbreaks in Brazil.

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