Awareness of risk and prevention of mosquito bites are the most important measures to take right now, health officials say.
A significant increase in the number of cases of Ross River virus has prompted a warning from Queensland’s top doctor.
The Sunshine Coast, Metro North, Metro South, Gold Coast, and Wide Bay are flagged as areas that have seen large rises in cases from last year.
Most of the cases so far in 2024 have been seen in South-East Queensland, with totals six to eight times higher than the five-year average of that area. The rest of Queensland has seen case rates rise 2.4 times higher than the five-year average.
The state’s last significant Ross River virus outbreak was in 2020, with 3381 cases reported. Currently, reported cases in Queensland were at 2114, according to the National Notifiable Disease Surveillance System (as of 30 April).
Case numbers have been considerably lower in other states and territories so far this year, with Ross River virus symptoms include fever, rash, and swollen and painful joints. There is no treatment other than symptom management. While the majority of people will recover in a few weeks, joint pain and fatigue can be experienced for months after the infection.
Queensland’s Acting Chief Health Officer Dr Catherine McDougall stressed the importance of year-round protective measures against the 40-plus species of mosquitos in Australia that carry Ross River virus.
“There’s no vaccine or specific antiviral treatment available for Ross River virus, so prevention is key. The most important measure you can do to protect yourself against mosquito-borne diseases is to take steps to avoid getting bitten,” she said in a statement.
She suggested avoiding outdoor activities when mosquitos are most active such as at dusk or dawn but said that bites can be experienced at any time of the day so covering exposed skin and applying DEET-based insect repellent regularly are good practices to adopt.
Queensland Health consultant medical entomologist, Dr Cassie Jansen, said Queensland was one of the only places in the world that routinely tested for mosquito-borne viruses by sampling mosquito saliva, which allowed for rapid risk assessment.
“It is also a useful tool to adapt to new virus threats as they emerge,” she said, citing the 2022 Japanese encephalitis virus outbreak, which allowed health officials to rapidly incorporate JEV testing into standard screening to accurately assess risk in the community.
Dr McDougall said that the surveillance from this 2023-2024 season (November-April) had returned the highest number of positive tests for Ross River virus in any one season during the program’s history.
