The disease is spread by mosquito bites and “very high” levels of the virus have already been detected in mosquitoes across the state, Queensland’s chief health officer John Gerrard said.

“It’s a very sudden uptick, a very sudden rise,” he told reporters on Monday.

There have been 31 cases detected in mosquito traps across the Brisbane, Wide Bay, Bundaberg, Banana, Gold Coast, Fraser Coast, Livingstone, Mackay, Sunshine Coast and Moreton Bay regions.

That’s more than the total number of positive traps recorded in the 2019-2020 summer months.

In 2020, there were 3381 cases of Ross River virus in Queensland.

“It’s very concerning that we’re seeing a large number of detections this early in the season,” Dr Gerrard said.

There have been 64 cases of Ross River reported in Queensland this year and the number is expected to skyrocket.

“It’s likely to be thousands,” he said.

“We’re talking a large number of Queenslanders who will get it.”

Symptoms of Ross River virus include fever, swollen and painful joints and a rash.

There is no vaccine or specific antiviral treatment so the best way to prevent Ross River virus infection is to avoid mosquito bites.

Dr Gerrard advised wearing insect repellent, avoiding outdoor activities at dusk and dawn when many mosquito species are most active, and wearing clothing which covers arms, legs and feet.