Report of natural Mayaro virus infection in Mansonia humeralis (Dyar & Knab, Diptera: Culicidae)

Abstract

Background: Arboviruses are a group of viruses transmitted to vertebrate hosts by certain blood-feeding arthropods. Among urban vectors of arboviruses, mosquitoes of the genus Aedes are the most common. However, other mosquitoes may be susceptible to infection and involved in the transmission, such as Mansonia spp. Therefore, this study aimed to investigate whether Mansonia humeralis can be infected with the Mayaro virus (MAYV).

Methods: These insects were collected from 2018 to 2020 in chicken coops of rural communities in Jaci Paraná in Porto Velho, Rondônia, Brazil, while performing blood-feeding on roosters. The mosquitoes were randomly grouped in pools from which the head and thorax were macerated and checked for the presence of MAYV by quantitative reverse transcription polymerase chain reaction (RT-qPCR). The positive pools were used to infect the C6/36 cell line, and on different days post-infection, the supernatant of the infected cells was subjected to viral detection by RT-qPCR.

Results: A total of 183 pools of female mosquitoes were tested, of which 18% were positive for MAYV; some samples from insect pools inoculated into C6/36 cells showed in vitro multiplication capacity between 3 and 7 days post-infection.

Conclusions: This is the first report of Ma. humeralis mosquitoes that are naturally infected by MAYV, indicating that these vectors may be potential transmitting agents of this arbovirus.

Keywords: Arboviruses; Mansonia humeralis; Mayaro fever; Viral isolation.

Fig. 1

Monitoring of the effect of MAYV inoculation in C6/36 cells after 1, 3, and 7 days. The images were analyzed by phase-contrast microscopy, with ×40 magnification. The culture supernatant at these time points was collected and analyzed by RT-qPCR