Transmission potential of Mayaro virus in Florida Aedes aegypti and Aedes albopictus mosquitoes.

ABSTRACT

Mayaro virus (MAYV) is an emerging mosquito-borne arbovirus present in Central and South America that causes arthralgia and febrile illness. Domestic mosquitoes Aedes aegypti (Diptera Culicidae) and Aedes albopictus are potential vectors of MAYV that may allow for transmission to humans in urban settings. The present paper assesses susceptibility to infection, disseminated infection and transmission potential in Florida Ae. aegypti and Ae. albopictus for MAYV. Oral infection was significantly higher in Ae. albopictus (85-100%) than in Ae. aegypti (67-82%). Viral dissemination to the haemocoel in Ae. aegypti and Ae. albopictus mosquitoes was rapid and co-occurred with infection of the salivary glands. Rates of disseminated infection were generally higher in Ae. aegypti (45-85%) than in Ae. albopictus (38-76%), although the difference was significant only at 9 days after feeding on MAYV-infected blood. Both mosquito species exhibited low rates of MAYV infection in saliva expectorates. Viral titres in the bodies of mosquitoes increased in line with the number of days post-blood feeding and were higher in Ae. aegypti than in Ae. albopictus. Although Florida mosquito vectors have the potential to transmit MAYV and thus to initiate an urban cycle after having fed on higher titres of MAYV-infected blood, lower viraemia in infected humans is likely to limit transmission potential.