Vector Competence of New Zealand Mosquitoes for Selected Arboviruses

New Zealand (NZ) historically has been free of arboviral activity with the exception of Whataroa virus (Togaviridae: Alphavirus), which is established in bird populations and is transmitted by local mosquitoes. This naive situation is threatened by global warming, invasive mosquitoes, and tourism. To determine the threat of selected medically important arboviruses to NZ, vector competence assays were conducted using field collected endemic and introduced mosquito species. Four alphaviruses (Togaviridae): Barmah Forest virus, Chikungunya virus, Ross River virus, and Sindbis virus, and five flaviviruses (Flaviviridae): Dengue virus 2, Japanese encephalitis virus, Murray Valley encephalitis virus, West Nile virus, and Yellow fever virus were evaluated. Results indicate some NZ mosquito species are highly competent vectors of selected arboviruses, particularly alphaviruses, and may pose a threat were one of these arboviruses introduced at a time when the vector was prevalent and the climatic conditions favorable for virus transmission.