13 March 2012

NSW Health is warning residents across the state to take extra precautions and protect themselves against mosquitoes following the recent heavy rains and floods across NSW.

The warning applies to people visiting or living in bush areas in and around Sydney, as well as regional and rural areas.

Mosquito borne infections are more prevalent in autumn and recent rain and flooding have led to increased mosquito breeding. Mosquito surveillance has already found increasing mosquito numbers in a number of locations around the state.

People need to take steps to avoid mosquito bites - protect yourself with clothing and repellent, protect your home with screens and remove collections of water around the house where mosquitoes can breed.

NSW Director of Health Protection, Dr Jeremy McAnulty, said the next few weeks will be ideal breeding conditions for mosquitoes which carry human diseases like Ross River virus, Barmah Forest virus, Kunjin virus, and Murray Valley Encephalitis virus.

“These infections can cause symptoms including tiredness, rash, fever, and sore and swollen joints. The symptoms usually resolve after several days, but some people may experience these symptoms for weeks or even months,” Dr McAnulty said.

“While the number of reported human cases of mosquito borne infections have not been very high so far this year, with 94 cases of Ross River virus and 56 cases of Barmah Forest virus notified in January and February 2012, case numbers usually rise in the autumn months, particularly with the kind of weather conditions we have seen this year,” Dr McAnulty said.

Avoiding mosquito bites will be especially important now and until at least after Easter when many people may be enjoying outdoor activities such as camping or fishing in areas with high mosquito numbers.

Mosquitoes that carry these viruses are usually most active in the hours after sunset and again around dawn. Simple steps to avoid being bitten by mosquitoes include:

  • When outside cover up as much as possible with light-coloured, loose-fitting clothing and covered footwear.
  • Use an effective repellent on all exposed skin. Re-apply repellent every few hours, as protection wears off from perspiration, particularly on hot nights. The best mosquito repellents contain Diethyl Toluamide (DEET) or Picaridin
  • The stronger the concentration of an insect repellent, the less frequently it will need to be applied to stop mosquito bites. Repellents containing low concentrations of DEET or Picaridin provide shorter periods of protection and need to be reapplied more frequently so it's important to read the product information
  • Topical repellents are not recommended for use on children under 3 months. Use of physical barriers such as netting of prams, cots and play areas is preferred. Repellents containing less than 10% DEET or Picaridin are safe for older children if applied according instructions. Parents or carers should apply repellent
  • Light mosquito coils or use vaporising mats indoors. Devices that use light to attract and electrocute insects are not effective
  • Cover all windows, doors, vents and other entrances with insect screens
  • When camping, use flyscreens on caravans and tents or sleep under mosquito nets.

Some types of mosquitoes like to breed around homes, even those in cities and towns, so people should also take steps to remove potential mosquito breeding sites around the home. This includes any container that holds water such as buckets, tyres, tarpaulins and black plastic, pot plant bases, aluminium cans and plastic containers.

For copies of fact sheets go to: