Recent heavy rains and flooding are likely to result in larger numbers of mosquitoes, prompting the North Coast Area Health Service’s  Public Health Unit to issue a public health alert for residents and visitors to guard against becoming infected with the mosquito-borne Barmah Forest and Ross River viruses.

“The heavy rains last week combined with high humidity and the possibility of further rain and some very high tides in the next few weeks means more breeding sites for mosquitoes. So we are expecting very high adult mosquito populations to emerge this week and over the coming weeks,” said NCAHS Director of Public Health Paul Corben

“With more mosquitoes maturing over the coming weeks, there will be a greater chance of being bitten and contracting a mosquito-borne virus. 

“This is also the time of year when we usually see a steep rise in cases of Barmah Forest virus and Ross River virus infections, so it’s particularly important that people take precautions against being bitten by mosquitoes over the coming several weeks.”

Symptoms of infection with Ross River virus or Barmah Forest virus are similar and include:

Flu-like symptoms, with fever chills, headache, and aches in the muscles and joints.

Some people may develop joint swelling and stiffness, especially in the mornings.

A rash sometimes develops, usually on the trunk or limbs. This rash usually disappears after 7 to 10 days.

A feeling of tiredness or weakness can occur at times during the illness, which can affect lifestyle and work performance.

The health service says the majority of people will recover completely within a few weeks. Others may experience symptoms on and off for more than three months and, in very rare cases, people may experience symptoms for longer periods.

A full recovery can be expected. About 300 cases of each of these illnesses are reported on average each year. Larger outbreaks occur after flooding.

The Public Health Unit urges people to protect themselves against mosquito bites by wearing light, loose clothing covering arms and legs, using a personal insect repellent containing the chemical diethyl toluamide (DEET) or picaridin and staying protected at dawn and dusk when mosquitoes are most active. 

Exposure to mosquitoes can be further minimised by using a knock-down insecticide indoors, installing and properly maintaining flyscreens on windows and doors and covering rainwater tanks without a lid with mesh.

Mosquitoes will breed in any receptacle that can hold water. The risk of being bitten can be reduced around the home by emptying old tyres, unused fish ponds, pot plant holders and any other place where stagnant water is present.

“The best ways of protecting yourself and your family from these viruses is to avoid being bitten by mosquitoes and to reduce breeding sites around your home,” Mr Corben said,

Fact sheets containing further information about Ross River virus and Barmah forest virus are available on the NSW Health website at