ROSE RIVER VIRUS IN MOSQUITOS (DIPTERA, CULICIDAE) DURING THE 1994 EPIDEMIC AROUND BRISBANE, AUSTRALIA

During the summer 1994 outbreak of epidemic polyarthritis in suburban Brisbane, 29,931 adult female mosquitoes were collected by octenol-CO2 light traps and tested for virus by species in pools of approximate t o 20 using an in situ enzyme-linked immunoassay. Overall, 63 isolation s of Ross River (RR) virus were made from 7 different mosquito species , including 23 from freshwater-breeding Culex annulirostris Skuse, 13 from peridomestic Aedes notoscriptus (Skuse), 4 from Aedes procax (Sku se), 12 from the brackish water-breeding Aedes funereus (Theobald), 9 from saltmarsh Aedes vigilax (Skuse), and 1 each from Culex sitiens Wi edemann and Aedes alternans (Westwood). The RR virus minimum infection rate in mosquitoes ranged from 1.6 to 2.5/1,000 from March to June 19 94. This study implicates freshwater and brackish water mosquitoes as important suburban vectors of RR virus and indicates the need for refo cusing mosquito control priorities.