Mozzie 'tornado' swarm prompts call for action at Lake Cathie

North Coast Public Health has issued a warning to Port Macquarie-Hastings residents of a spike in mosquito-borne diseases this year as perfect weather conditions matched by recent rain and humidity combine in a breeding frenzy.

The number of people contracting Ross River and Barmah Forest viruses in the region has doubled.

Lisa Willows at Lake Cathie captured a swirl of mozzies over her property and fly screens on her home infested with the little bug that can potentially leave more than just an irritating bite.

Public Health Director Paul Corben said recent warm weather had been favourable to mosquito breeding late in the season with the viruses detected in mosquitoes trapped at several locations across the NSW North Coast.

"Ross River and Barmah Forest viruses can be common in the region and are transmitted by infected mosquitoes that breed in flooded, grassy and swampy areas and around waterways," he said.

"This year, 113 residents have been diagnosed with Ross River virus and 32 with Barmah Forest virus in the region which stretches from Laurieton to the Queensland border. Of these cases, 89 have been reported in the past four weeks - approximately double those for the same period in 2019."

Symptoms include tiredness, rash, fever, and sore and swollen joints. These usually resolve after several days but some may be experienced for weeks or even months.

Ms Willows, and Saving Lake Cathie spokesperson Stewart Cooper, said something must be done to get water moving out of the stagnant lake which has now become a prime breeding location for disease-ridden mozzies.

Mr Corben added that extra precautions must be taken if going outside in the peak mosquitoes times - early morning and on dusk - to avoid being bitten and potentially contracting Ross River Fever or Barmah Forest.

"We have seen a seasonal spike which is normal for this time of year but the virus has been detected in the mosquitoes we have trapped in the Port Macquarie-Hastings area," Mr Corben added.

Stop adult mosquitoes entering the home by using flyscreens on windows and doors, and screening chimneys, vents and other entrances. Repair any damaged screens.

Also consider using a surface insecticide spray in areas where mosquitoes like to rest. During the day, mosquitoes rest and hide in cool shady areas such as in and around the home before emerging at dusk to feed. Make sure you avoid aquaria and fish ponds as fish are acutely sensitive to these insecticides.

Mosquitoes need water to breed and some mosquitoes can breed in very small amounts of water, such as in the water that collects in a discarded soft-drink can. Measures to reduce the risk of mosquitoes breeding in around the home include:

Properly cleaned and chlorinated swimming pools are rarely a source of mosquito breeding but neglected pools can be a haven for mosquitoes.

Visit NSW Health website for more information.