High risk for chikungunya virus to initiate an enzootic sylvatic cycle in the tropical Americas

Abstract

BackgroundChikungunya virus (CHIKV) has dispersed in the Americas since 2013, and its range of distribution has overlapped large forested areas. Herein, we assess vector competence of two sylvatic Neotropical mosquito species, Haemagogus leucocelaenus and Aedes terrens, to evaluate the risk of CHIKV to initiate a sylvatic cycle in the continent.Methodology/Principal findingsHaemagogus leucocelaenus and Ae. terrens from the state of Rio de Janeiro, Brazil were orally challenged with the two CHIKV lineages circulating in the Americas. Fully engorged females were kept in incubators at 28±1°C and 70±10% humidity and examined at 3 and 7 days after virus exposure. Body (thorax plus abdomen), head and saliva samples were analyzed for respectively determining infection, dissemination and transmission. Both Hg. leucocelaenus and Ae. terrens exhibited high infection and dissemination rates with both CHIKV isolates at 7 dpi, demonstrating that they are susceptible to CHIKV, regardless of the lineage. Remarkably, Hg. leucocelaenus expectorated infectious viral particles as rapidly as 3 days after the infectious blood meal, displaying higher values of transmission rate and efficiency than Ae. terrens. Nevertheless, both species were competent to experimentally transmit both CHIKV genotypes, exhibiting vector competence similar to several American Aedes aegypti.Conclusions/SignificanceThese results point out the high risk for CHIKV to establish a sylvatic transmission cycle in the Americas, which could be a serious health issue as CHIKV would become another zoonotic infection difficult to control in the continent.

Role of monkeys in the sylvatic cycle of chikungunya virus in Senegal

“…Moreover the hunt for CHIKV reservoir hosts has increased in urgency since 2013, when CHIKV was introduced into the Americas. Recently, Loureno-de-Oliviera and Failloux have shown that several neotropical, sylvatic, primatophilic mosquito species are highly competent vectors for CHIKV, opening the door to spill-back of CHIKV from humans to New World primates [45]. However it is possible, based on the data presented here, that other host species will also be required if CHIKV is to establish a sylvatic cycle in the Americas [23,46].…”

The vertical stratification of potential bridge vectors of mosquito-borne viruses in a central Amazonian forest bordering Manaus, Brazil

“…Such areas increase permeability for the co-occurrence of hosts and bridge vectors, thereby elevating the risk of zoonotic arbovirus exchange 54 . This has the potential to cause outbreaks of novel diseases in urban populations, or, as is the concern for Zika virus in the Americas, lead to spillback and establishment of sylvatic cycles of transmission that could result in an enduring threat to human health 1 , 55 . Understanding the ecology and behavior of potential bridge vectors is, therefore, critical to understanding the risk of spillover and spillback.…”

Arbovirus Vectors of Epidemiological Concern in the Americas: A Scoping Review of Entomological Studies on Zika, Dengue and Chikungunya Virus Vectors

“…aegypti [126,127,144,161–164,164–166], Ae. albopictus [127,144,162,164–167], Aedes terrens [168], and Haemagogus leucocelaenus [168] are all experimentally competent to transmit chikungunya virus. Chikungunya virus transmission in Ae.…”