Australia’s Ross River virus spike prompts mosquito warning across NSW Riverina

Mosquito biting human skin.

New South Wales Health authorities renew warnings for residents and holiday makers in the state’s Riverina region to protect themselves against mosquitoes after a fivefold increase in the number of Ross River virus infections compared to the average in previous years.

NSW Public Health Director Tracey Oakman said there were 34 cases of the virus in the Murrumbidgee Local Health District in December, five times the average for this time of year.

“The highest number of notifications have been in the 45- to 65-year-old age group and then the next age group most commonly notified is the 25- to 44-year-old age group,” she said.

The city of Griffith has been flagged as a hotspot for the virus, with seven cases reported in the region last month.

Ms Oakman also said a number of holiday makers in the Riverina who contracted the disease were unlikely to have been picked up in the latest figures.

“If we’ve got holiday makers that have been bitten and gone home, they’ll be recorded as having the virus from the postcode that they’re living in,” she said.

Ms Oakman said the numbers were concerning and she urged people to be vigilant, use quality mosquito repellents and wear long clothing.

How is the virus spread?

Ross River virus is spread among humans by the bite of certain types of infected female mosquitoes, which generally pick up the virus when feeding on the blood of infected animals.

Outbreaks can occur when local conditions of rainfall, tides and temperature promote mosquito breeding.

Tips to beat bites

  • Wear long, loose-fitting clothing
  • Use effective mosquito repellents containing DEET or picaridin
  • Control mosquitos with sprays or vaporising devices for inside use, including caravans
  • Install fly screens
  • Make sure mosquitos can’t breed by removing stagnant water every week
  • Empty children’s wading pools when not being used
  • Limit outdoor activity at dusk and dawn

Source: Department of Health 


Ms Oakman said mosquito numbers had flourished after months of wet weather.

“That’s really concerning because we don’t normally see such a high level of Ross River virus in December.

“We normally get higher cases in February, March and April, the tail end of summer.

“Seeing them this early is a real concern,” she said.

Ms Oakman warned that wet conditions were likely to lead to even more people contracting the virus across the region in the coming months. She called on people who became infected to visit the doctor.

“The symptoms … joint aches and pains, headaches, fever, a chill and sometimes a rash,” she said.

“Sometimes the symptoms persist for weeks and even months.

“It’s quite a miserable time for someone who contracts it.”

Reported by ABC News on 6 January 2017.