WA health officials are bracing for one of the worst mosquito seasons in recent memory after an unusually wet spring and early detections of the debilitating Ross River virus.
The Health Department issued an alert yesterday confirming the detections and warning South West residents and holidaymakers they would need to take extra precautions against the risk of mosquito bite this summer.
The department's Michael Lindsay said though there had been only 12 reported cases of Ross River virus in the South West since July 1, indications suggested the coming mosquito season could be historically bad.
Dr Lindsay said larvae numbers along the coastal strip between Busselton and Mandurah were high because of a late and wet winter, which inundated lowlying areas and provided more breeding habitat.
He said the prospect of higher-than-normal tides this spring could exacerbate the risks associated with increased mosquito numbers because they would push breeding grounds inland during the warmer months.
"It will be time that tells whether this does develop and a lot of that will hinge on just how much more rainfall we get through the last couple of weeks of October and into November," Dr Lindsay said.
"We're right at the very early part of the season with low numbers of cases reported from those areas.
"But our concern is that that may translate into much larger numbers of cases if conditions continue as they are and if people don't take adequate precautions to protect themselves."
The department urged people to take their own precautions while warning it was not realistic to expect the State and local governments to completely safeguard them.
They could do this by wearing long sleeves, avoiding mosquito-prone areas at dawn and either side of dusk and using a personal repellent containing diethyltoluamide or picaridin on exposed skin.
Dr Lindsay, the department's managing scientist of environmental health hazards, appealed to households to remove containers holding stagnant water.
There are fears this summer could be worse than 2011-12, when more than 700 people were infected with Ross River virus in Perth alone.
Australian Medical Association WA president Richard Choong echoed calls for individuals to take safeguards but suggested the State could do more to suppress mosquito numbers.
Dr Choong, whose Port Kennedy GP clinic often treats Ross River virus patients, said its symptoms were serious and included fever, rash, joint pain and aching muscles, which could persist for months.
"Governments tend to ignore this purely because Ross River doesn't kill anyone," Dr Choong said. "They don't take into account that it is very debilitating for those who have it."