Mosquito fauna (Diptera: Culicidae) in an Atlantic Forest remnant urban park and report of Chikungunya virus RNA detection in sylvatic mosquitoes.

Patches of Atlantic Forest within urban areas in Brazil may provide suitable conditions for the establishment of transmission cycles of emerging alphaviruses and orthoflaviviruses due to the presence of potential hosts, such as non-human primates, and competent vectors. This study aimed to characterize the diurnal mosquito fauna and detect arboviruses in an Environmental Protection Area in the city of Aracaju, Northeast Brazil, where dengue, zika, and chikungunya are endemic. Entomological surveys and molecular assays were conducted to detect viral infection in adult mosquitoes. Ovitraps were used to collect immature stages in two environments of the park: open and forested areas. Aedes albopictus was the most abundant species among the three species of immatures collected in ovitraps. A total of 658 adult mosquitoes were collected by aspiration, yielding 11 species Ae. albopictus again being the most abundant, followed by Ae. scapularis. Chikungunya RNA was detected in Ae. albopictus, Ae. scapularis, and mixed pools of Wyeomyia spp. The main findings of the study were the dominance of the invasive species Ae. albopictus, and the detection of CHIKV RNA in both synanthropic and sylvatic mosquito species. The detection of CHIKV RNA in native forest mosquitoes raises the possibility that sylvatic mosquito communities are being exposed to urban circulating arboviruses, although the epidemiological significance of this finding remains unclear. No sylvatic yellow fever primary vectors were recorded in this survey.