THEME infectionS tHAt LASt

Ross River virus (RRV) is a mosquito transmitted alphavirus that causes epidemic polyarthritis and arthralgias, with about half of patients also experiencing fever and rash. it is Australia’s most common arbovirus with about 5000 cases notified every year (Figure 1).1 The first documented outbreak of RRV occurred in 1928 in Narranderra and Hay in New South Wales2,3 with subsequent outbreaks described during World War II among troops in the Northern Territory4 and Queensland.5 The virus was isolated in 1959 from an Aedes vigilax mosquito along the Ross River near Townsville in Queensland,6 although it was not until 1985 that it was isolated from an Australian patient with polyarthritis.7 Outbreaks have since occurred in all Australian states, including Tasmania, and have occurred i