Significant rainfall increases mosquito risk

9 November 2010

Hunter New England Health is warning people living in the region to take precautions against mosquitoes.

A general increase in mosquito activity has followed rainfall across the Region that has provided many breeding sites for mosquitoes.

Salt-marsh mosquitoes in coastal areas can be carriers of Barmah Forest infection, while fresh-water breeding mosquitoes inland can transmit Ross River Fever.

In addition the last large outbreak of Murray Valley virus infection in western NSW followed similar heavy rainfall in central Australia some 35 years ago.

Public Health Physician Dr Tony Merritt advises that the best way to prevent infection is to avoid being bitten by mosquitoes, which spread all three mosquito borne virus infections.

“These viruses are spread by mosquitoes that feed on animals that have the infection,” Dr Merritt said.

“Good rainfall in the affected areas has contributed to a rise in mosquito breeding. The warm weather allows mosquitoes to survive longer and transmit viruses to people.”

Dr Merritt said symptoms for Barmah Forest and Ross River virus infection include fever, skin rash, painful joints and tiredness.

Murray Valley infection may cause mild flu-like illness but in severe cases, can result in encephalitis, an acute infection of the brain, and even death.

“As there is no specific treatment for these mosquito borne viruses, prevention depends on avoiding mosquito bites, especially in the summer and autumn months when infections peak, and minimising potential mosquito breeding sites,” Dr Merritt said.

“Mosquitoes breed in places such as pools, gutters and containers. It’s time to clean up around the home to ensure you are not providing a breeding ground for mozzies.”

Other natural mosquito breeding sites include coastal estuaries and areas near rivers, dams and lakes. It only takes two to three weeks to produce large numbers of mature mosquitoes.

Methods for avoiding mosquito bites include:

• avoiding being outside unprotected before dawn and after dusk
• avoiding known high risk breeding sites, including marsh areas
• when outside wearing loose fitting, light coloured clothes that cover your arms and legs
• using an insect repellent, that contains the chemical DEET or picaridin, on exposed skin
• fitting fly screens to all windows and doors and keeping these in good repair
• if mosquitoes are inside, using a knockdown insecticide in bedrooms half an hour before going to bed according to instructions

Contact: Sharna McCarthy

Phone: 49424812