Vector competence of Aedes aegypti from Havana, Cuba, for dengue virus type 1, chikungunya, and Zika viruses.

Author summary Dengue (DENV), Zika (ZIKV), and chikungunya (CHIKV) viruses are mainly transmitted by Aedes aegypti mosquitoes and together caused near 10 million human cases in the last decade in the Americas. The diseases caused by these viruses share symptoms ranging from mild clinical manifestations to severe complications, including fatal outcomes. Cuba has not been exempted from these viruses and is frequently subjected to dengue and more recently by diseases caused by ZIKV infection. Surprisingly, despite multiple CHIKV outbreaks recorded in neighboring countries, local circulation has not been reported in Havana. Although Ae. aegypti has been implicated as the major DENV and ZIKV vector because of its wide distribution on the island, neither field nor experimental approaches have been used to demonstrate the ability of Cuban Ae. aegypti populations to transmit DENVs, ZIKV, and CHIKV. In this laboratory study, we demonstrated that two Ae. aegypti populations from Havana could become infected with and transmit these viruses, albeit at low rates. Our paper suggests that the absence of CHIKV circulation in Havana was not related to refractoriness of Ae. aegypti populations to this virus; therefore, vector control remains being essential in preventing future arboviruses outbreaks. Background Like many countries from the Americas, Cuba is threatened by Aedes aegypti-associated arboviruses such as dengue (DENV), Zika (ZIKV), and chikungunya (CHIKV) viruses. Curiously, when CHIKV was actively circulating in the region in 2013-2014, no autochthonous transmission of this virus was detected in Havana, Cuba, despite the importation of chikungunya cases into this city. To investigate if the transmission ability of local mosquito populations could explain this epidemiological scenario, we evaluated for the first time the vector competence of two Ae. aegypti populations (Pasteur and Parraga) collected from Havana for dengue virus type 1 (DENV-1), CHIKV, and ZIKV. Methodology/Principal findings Mosquito populations were fed separately using blood containing ZIKV, DENV-1, or CHIKV. Infection, dissemination, and transmission rates, were estimated at 3 (exclusively for CHIKV), 7, and 14 days post exposure (dpe) for each Ae. aegypti population-virus combination. Both mosquito populations were susceptible to DENV-1 and ZIKV, with viral infection and dissemination rates ranging from 24-97% and 6-67% respectively. In addition, CHIKV disseminated in both populations and was subsequently transmitted. Transmission rates were low (<30%) regardless of the mosquito population/virus combination and no ZIKV was detected in saliva of females from the Pasteur population at any dpe. Conclusions/Significance Our study demonstrated the ability of Ae. aegypti from Cuba to transmit DENV, ZIKV, and CHIKV. These results, along with the widespread distribution and high abundance of this species in the urban settings throughout the island, highlight the importance of Ae. aegypti control and arbovirus surveillance to prevent future outbreaks.