Anopheles mosquitoes may drive invasion and transmission of Mayaro virus across geographically diverse regions

Abstract

The Togavirus (Alphavirus) Mayaro virus (MAYV) was initially described in 1954 from Mayaro County (Trinidad) and has been responsible for outbreaks in South America and the Caribbean. Imported MAYV cases are on the rise, leading to invasion concerns similar to Chikungunya and Zika viruses. Little is known about the range of mosquito species that are competent MAYV vectors. We tested vector competence of 2 MAYV genotypes in laboratory strains of six mosquito species (Aedes aegypti, Anopheles freeborni, An. gambiae, An. quadrimaculatus, An. stephensi, Culex quinquefasciatus). Ae. aegypti and Cx. quinquefasciatus were poor MAYV vectors, and had either poor or null infection and transmission rates at the tested viral challenge titers. In contrast, all Anopheles species were able to transmit MAYV, and 3 of the 4 species transmitted both genotypes. The Anopheles species tested are divergent and native to widely separated geographic regions (Africa, Asia, North America), suggesting that Anopheles may be important in the invasion and spread of MAYV across diverse regions of the world.

The RNAi Pathway Is Important to Control Mayaro Virus Infection in Aedes aegypti but not for Wolbachia-Mediated Protection

“…This is in agreement with previous published data suggesting that Ae. aegypti could play a significant role in the transmission of MAYV [10][11][12][13]. Moreover, we also provided evidence that Wolbachia induces resistance to MAYV infection in Ae.…”

Neutralizing antibodies against Mayaro virus require Fc effector functions for protective activity

“…Aedes mosquitoes can be infected by MAYV, although the levels of virus in blood required for transmission from viremic humans are considered insufficient for epidemic transmission (Brustolin et al, 2018). In comparison, four different Anopheles mosquitoes can transmit MAYV (Brustolin et al, 2018). As these species are native to distinct geographic regions (Africa, Asia, and North America), they could facilitate the global spread of MAYV.…”

Transmission potential of Mayaro virus by Aedes albopictus, and Anopheles quadrimaculatus from United States

“…Anopheles mosquitoes are persistently exposed in nature to diverse arboviruses, but in general assessment of their potential to transmit arboviral pathogens has been neglected. In addition to MAYV, vector competence of Anopheles mosquitoes for O'nyong nyong (ONNV) virus, Rift Valley fever phlebovirus, Eastern equine encephalitis virus, and Cache Valley orthobunyavirus have been reported [12,[24][25][26]. However, only ONNV is known to rely on Anopheles spp as primary vectors [27,28].…”

“…[7,10]. Moreover, Aedes albopictus, Aedes aegypti, Anopheles gambiae, Anopheles stephensi, Anopheles quadrimaculatus and Culex quinquefasciatus are known to be competent vectors [12][13][14].…”