Western Australia has recorded the highest number of cases of the mosquito borne virus Ross River in over a decade.
There were 1579 cases state wide last financial year compared to less than half that number the year before.
The Health Department says the biggest spikes have been in the Perth metropolitan area, the South-west and the Great Southern.
Acting Medical Entomologist Peter Neville says the large increase is not surprising.
"For the last year, we've been under La Nina weather conditions," he said.
"This means that we've seen much higher than average rainfall, warmer minimum temperatures and an increase in the number and frequency of high tides.
"There's a natural desire for most people to actually live close to rivers and lakes. Unfortunately that's where the mosquitoes are breeding."
© ABC 2012
17:17 EST A 40-year-old man has been sentenced to a year in prison for fraudulently claiming money from the Queensland Flood Appeal.