Dose-dependence of susceptibility and transmission for an Argentinean West Nile virus strain in local Culex pipiens quinquefasciatus (Diptera: Culicidae)

Abstract

West Nile virus (WNV) activity was documented in the central region of Argentina since 2005, but its maintenance network is not dilucidated yet. We evaluated the susceptibility to WNV oral infection and transmission in a Cx. p. quinquefasciatus mosquito population by mean of a dose-dependent vector competence assay. Mosquitoes were orally infected with 5 different viral loads and evaluated vector competence. The evaluated population was susceptible to WNV oral infection. Disseminatedinfectionswere detected at all viral doses but transmission only at higher doses (6 and 7 log10 PFU/ml). We were able to establish a linear relationship between doses and rates. Finally, minimum transmission threshold suggests that Cx. p.quinquefasciatus from Argentina could acquire WNV infection from autochthonous urban birds and transmit the virus.