Vector competence of Argentinean Aedes aegypti population for different strains of Zika virus

Abstract

Background: Since the emergence of Zika virus (ZIKV; Flaviviridae; Flavivirus) in Brazil in 2015, the virus has spread quickly in 48 countries along the American continent resulting in millions of infections. Although these infections usually cause a mild illness, the virus is also associated with serious congenital disease and other neurological disorders as Guillain-Barré syndrome, which makes ZIKV an important target of study. Moreover, a few cases of sexual transmission were reported suggesting an alternative route of transmission. In Argentina the first outbreak was detected in San Miguel de Tucumán in 2016, followed by others during 2017 in Salta, Formosa and Chaco provinces, causing many human infections. However, there is no report of ZIKV isolation in mosquito, remaining the question about which mosquito species are involved in vector transmission in Argentina. Methods & Materials: In order to assess vector competence, an autochthon population of Aedes aegypti from Buenos Aires province was artificially fed with two ZIKV strains, one of them isolated from an autochthon case and the other from an imported case from Venezuela. At seven and fourteen days post-inoculation (DPI), bodies, legs, and saliva were harvested from each mosquito in order to evaluate transmission, dissemination and infection rates for ZIKV. Results: So far, studies by real-time PCR for ZIKV in the body of each mosquito were carried out for the Venezuelan strain. Preliminary results show that infection rates are higher at 14 DPI than at 7 DPI. However, transmission, dissemination and infection rates data for both strains are still being analyzed. Conclusion: The different transmission pathways of this flavivirus point out a complex scenario in the epidemiology of this disease. This study, focused on the vector competence of local vector populations and ZIKV strains, could contribute to understand the dynamics of this disease in Argentina.