The high-pitched buzz of a mosquito as it sails past your ear is not an unfamiliar sound in any Australian summer.
Subscribe now for unlimited access.
or signup to continue reading
And this season, it's something Australians may have to contend with even more as experts say mosquito numbers could grow with a wetter than average forecast ahead.
University of Sydney medical entomology associate professor Dr Cameron Webb said mosquitoes needed two key ingredients to complete their life cycle: Water and warmth.
"They need water for the immature stages to develop.
"All the rain and the flooding that we've experienced in recent weeks, and the rain is forecast to continue, will ensure there's lots of pools and puddles in the wetlands and [the] floodplains are all full of water," Dr Webb said.
The Bureau of Meteorology has forecast above-average rainfall for the coming months based on climate drivers, including a La Nina system and a natural climate phenomenon that influences weather patterns around the Indian Ocean, known as Indian Ocean Dipole.
Both are associated with warmer ocean temperatures near Australia that means more moisture over the continent and stronger low pressure systems in the south.
University of Queensland School of Biological Sciences associate professor Dr Nigel Beebe said there was a scenario with a La Nina system where there was too much rain for the insects to survive.
"Water sitting in the landscape will generate mosquitoes but, if it's really pouring down, [flooding] will flush the larvae away so [we] might initially see a decrease and then [an] increase," Dr Beebe said.
"The worst case scenario for mosquitoes is long, protracted light rain that doesn't flush out the local sites but just keeps enough water in the landscape so that mosquitoes can keep breeding."
This comes as new research by New York's Rockefeller University showed people who secrete more carboxylic acids from their skin were more attractive to mosquitoes.
Dr Beebe said different people may attract different mosquitoes.
"A mosquito will find a host by picking up at Co2 plume that it breathes out from a distance of like 40 to 50 metres ... and then when they get close, they make more subtle decisions based on olfactory cues, the smells, heat and things like that," he said.
"To a mosquito, everybody smells a bit different and that often has to do with the microbiome of bacteria that sits on your skin.
"Some people in some parts of Australia might always be attractive to mosquitoes, when their partner isn't, but if they move to another part of Australia where there are different types of mosquitoes it might flip around."
READ MORE:
Mosquito-spread Japanese Encephalitis Virus (JEV) has been in the spotlight this year since the illness was found in piggeries across Victoria, Queensland and NSW in February.
If symptoms of JEV occur, they can include fever, headache, neurological complications or possibly death, and usually develop five to 15 days after being bitten by infected mosquitoes.
On March 4, the Australian JEV situation was declared a 'Communicable Disease Incident of National Significance'.
The latest release on JEV by the Department of Health for October 12 said there had been 32 human cases and 10 probable cases in Australia since January 1, 2021. Those case numbers comprise 13 each in NSW and Victoria, nine in South Australia, five in Queensland and two in the Northern Territory.
Across the outbreak, seven people have died as a result of JEV.
It is not known how the outbreak came to Australia.
Speaking to ACM a Health Department spokesperson said there were measures people could take to prevent bites and lower the risk of disease.
"There are simple steps we can all take to protect against mosquito-borne diseases such as wearing long, loose fitting clothes, using repellents containing picaridin or DEET on exposed skin and trying to limit outdoor activities if lots of mosquitoes are around," the spokesperson said.
"Residents and visitors in all areas of the state should be aware of the potential of mosquito-borne illness and the need to avoid being bitten."
Dr Webb added it was not only the type of products people used to avoid bites, but how they were used.
"You should be putting on a nice even coat over all exposed areas of skin because that will provide the longest lasting protection against mosquito bites," he said.
"Spread it around, cover as much of your exposed skin as possible, and that will provide the best protection against biting mosquitoes."
- Visit www.health.gov.au to keep up to date with national health alerts.
