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

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.

Possible Emergence of Zika Virus of African Lineage in Brazil and the Risk for New Outbreaks

“…This lineage displayed higher transmissibility in Aedes aegypti than ZIKV AS , and it was also verified to mosquitoes from South American (Aubry et al, 2021). Alencar et al (2021) found Ae. albopictus naturally infected with ZIKV AF in the Southeast of Brazil, recovered from the Atlantic Forest.…”

“…Eventually, these vectors may be carrying ZIKV, regardless of the lineages and supporting a possible establishment of a sylvatic cycle, critical for the arbovirus maintenance (Lowe et al, 2018;Giovanetti et al, 2020). Recently, ZIKV AF circulation in mosquitoes and NHPs in sylvatic areas in Brazil was evidenced (Figure 1) (de Almeida et al, 2019-Preprint publication; Alencar et al, 2021). This lineage displayed higher transmissibility in Aedes aegypti than ZIKV AS , and it was also verified to mosquitoes from South American (Aubry et al, 2021).…”

“…Recently, a study published by Kasprzykowski et al (2020) identified ZIKV AF present among Brazilian ZIKV sequences. ZIKV AF was identified in non-human primates (NHPs) and mosquitoes in the South and Southeast Brazilian regions, respectively (Figure 1) (de Almeida et al, 2019-Preprint publication;Alencar et al, 2021). At the same time, Aubry et al (2021) showed ZIKV AF being more transmissible in mosquitoes and more lethal in mice when compared to ZIKV AS .…”

An Updated Review of the Invasive Aedes albopictus in the Americas; Geographical Distribution, Host Feeding Patterns, Arbovirus Infection, and the Potential for Vertical Transmission of Dengue Virus

“…On the other hand, the Zika virus was identified in Ae. albopictus in six studies carried out in Brazil (n = 4) and Mexico (n = 2) [14,47,53,54,57,59].…”

“…Additionally, yellow fever virus was isolated in Ae. albopictus females in Rio de Janeiro State, which could imply that it could be acting as an additional jungle or rural vector causing a possible transmission bridge to the urban area [47].…”