Doctors warn of major ‘risk of Ross River virus and Japanese encephalitis’ as mosquitos swarm

Australians are being warned of an increased risk of illness as mosquito numbers increase over the Christmas and summer holiday period.

Doctors are urging people to take precautions to avoid mosquito bites as they can lead to contracting the deadly Ross River virus and Japanese encephalitis virus.

Queensland’s Chief Health Officer Dr Heidi Carroll said the state’s recent wet weather has created the perfect breeding conditions for mosquitoes, meaning numbers are set to rise.

“Mosquito numbers always increase significantly in wet and warm weather, and Queenslanders should be extra vigilant against bites from now on,” Dr Carroll said.

‘With increased numbers of mosquitoes comes a greater risk of contracting mosquito-borne diseases such as Ross River virus and Japanese encephalitis virus (JEV)

‘Biting can occur at any time of the day, but some species are most active at dusk and dawn, so you need to be particularly vigilant at these times.’

Dr. Carroll said regular summer holiday activities at this time of year lead to a greater risk of falling prey to dangerous bites.

“If you go outside during the holiday season, such as walking in the bush, camping or enjoying backyard barbecues, you should take precautions against mosquitoes,” she said.

She said it was also important that everyone took measures to prevent mosquitoes from breeding and entering their homes.

“Make sure you take a walk around your house and empty any containers of water,” Dr. Carroll said.

‘You should also ensure that the fly screens are in good condition so that mosquitoes do not easily enter your home.’

Ross River virus infection is the most common mosquito-borne disease reported in Queensland.

“We normally see cases increase with the onset of rain and warm temperatures in December, before reaching their peak in February and March,” Dr Carroll said.

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

There is no vaccine or specific antiviral treatment available for Ross River virus.

People should also be aware of JEV, a rare but serious disease that can be transmitted to humans by infected mosquitoes.

“We have been notified by New South Wales health authorities that surveillance programs have identified JEV activity among feral pig and mosquito populations across the state, with some activity detected near the Queensland border,” Dr Carroll said.

This means there is likely an increased risk of JEV, she said.

‘Residents in the Far North, Darling Downs, South West and Wide Bay regions should be especially vigilant as JEV has been previously detected here in Queensland in recent years.’

Doctors are urging people to take precautions to avoid mosquito bites (pictured) as they can lead to contracting the deadly Ross River virus and Japanese encephalitis virus

Diseases caused by JEV are most common in pigs and horses, but can be transmitted to humans through bites from mosquitoes that become infected after biting infected animals.

“Although most people infected with the virus are asymptomatic, it can cause fever, headache and rash,” Dr. Carroll said.

‘In severe cases, the disease can cause serious neurological disorders, including convulsions.’

Steps to prevent mosquito bites

Apply insect repellent to exposed skin and reapply according to manufacturer’s instructions.

Use an effective mosquito repellent, preferably one that contains DEET, Picaridin or Lemon Eucalyptus Oil.

Wear loose, light-colored clothing to cover arms, legs and feet.

Use insecticide sprays, insecticide-based vapor dispensers and, if outdoors in a well-ventilated area, mosquito coils.

Make sure tents have screens to prevent mosquitoes from entering, or sleep under a mosquito net when camping.