HEALTH authorities are warning residents to stay on guard as the “perfect storm” of recent heavy downpours and king tides have created ideal breeding conditions for the dreaded mosquito.
The main offender is the salt marsh mozzie, which carries both Ross River and Barmah Forest viruses.
University of Sydney medical entomologist Cameron Webb said the blood-suckers have likely bred in significant numbers at hotspots such as Hexham swamp in recent weeks.
“We’ve just come out of quite a dry summer but recently we’ve had a pretty substantial amount of rain and king tides,” he said.
“Those two factors have created the perfect storm.”
Dr Webb said the good news is it will become too cold for mosquitoes to breed by the end April, but health authorities are expecting “peak numbers” between now and Easter.
There have been 18 cases of Ross River virus and five cases of Barmah Forest virus in the Hunter New England Health district this year.
Thanks to severely dry weather, the most recent figures stack up well compared with the 141 cases of Ross River virus recorded at the same time last year.
However, HNEH public health physician David Durrheim said the recent rain meant the outlook had changed.
“It’s a good time to get a warning out,” he said.
“The recent rain and king tides over the past two weeks means we can expect peak numbers at Easter. The conditions are more than adequate for breeding.”
Hotspots for mosquitoes include Hexham, Callaghan, Shortland, Blackbutt Reserve and Carrington.
But Dr Durrheim said anywhere with shade and a body of water is likely to attract mosquito plagues.
He encouraged residents to cover up, wear insect repellent and empty uncovered stocks of fresh water from backyards.
“There’s almost nowhere in Newcastle, Lake Macquarie and Port Stephens that is free of mosquitoes … it’s important people take precautions,” he said.
People infected with Ross River virus usually suffer fatigue and joint pain, and Dr Durrheim said in severe cases patients have been unable to get out of bed.
Dr Webb said Newcastle used to have one of the largest mosquito eradication programs in the country – where trucks used to spray for mozzies in the streets – but it had “unintended consequences” on other wildlife and was “inefficient” given the size of the city.
He said some solace could be found in the Hexham grey mosquito – of Ossie the Mozzie fame – which preys on the salt marsh mozzie.