 Aquatic weed issues in the river in recent years seem to have prevented this event from occurring as regularly as in the past (at least in this location).Ross River fever is a serious, though generally not life-threatening, tropical disease caused by infection by the Ross River virus, a mosquito-borne alphavirus.In 1959, an "Aedes vigilax" mosquito sampled from the banks of the Ross River was used to isolate the virus.