Aedes (Gymnometopa) Mediovittatus (Diptera: Culicidae), A Potential Maintenance Vector of Dengue Viruses in Puerto Rico1

Abstract

Unusually long persistence and continuous transmission of dengue viruses in rural communities of Puerto Rico during interepidemic periods led us to investigate possible maintenance mechanisms for these viruses. A consistent feature of the ecology in rural Puerto Rican communities was the presence of Aedes (Gymnometopa) mediovittatus mosquitoes breeding in the peridomestic environment. We investigated this species as a potential vector of dengue viruses. It was shown to feed readily on humans and to have a biting activity cycle with 2 peaks, one in the early morning and another, larger peak in the late afternoon and early evening. Laboratory studies showed that Ae. mediovittatus was similar to Ae. aegypti in its ability to support dengue virus replication, that it had a significantly higher susceptibility to oral infection with dengue 2 virus than Ae. aegypti, that the salivary glands of Ae. mediovittatus had extensive dengue virus infections, and that this species readily transmitted dengue virus to mice and to hanging-drop blood suspensions. Experimental transovarial transmission of dengue 1 virus by Ae. mediovittatus was demonstrated. Collectively, the data suggest that Ae. mediovittatus is an efficient host for dengue viruses and that this species may play an important role in the maintenance of dengue viruses in Puerto Rico during interepidemic periods.