GPs are being warned to check patients are protected against measles after a surge in cases in WA this year, including three children of "vaccine refuser" parents.
The WA Health Department says that despite Australia being declared measles-free, 17 cases were reported in the first three months of this year - the same number reported for the whole of 2011, which had the highest number of cases in recent years.
Those infected this year range in age from seven to 40.
In its latest disease bulletin, the department urges GPs to ensure that people travelling overseas, in particular, are fully vaccinated against measles.
Most cases of the highly contagious illness this year have been picked up in South-East Asia, including the Philippines, Indonesia and Thailand, and some of those infected have spread the virus to unvaccinated people in WA, including three children in one family whose parents were vaccine refusers.
Australian Medical Association WA president Richard Choong said the surge in cases this year was alarming, particularly as West Australians often travelled to regions with measles outbreaks, including the Philippines and Bali.
"Measles is on the rise in developing nations and this is very worrying because they are popular holiday destinations, and the big concern is when people bring back this disease and infect those who aren't immunised," he said.
"If it gets into a daycare centre where some very young children have not reached the age at which they can be fully immunised, they are totally exposed, with no inherent immunity because we don't usually see measles here."
Measles is spread through airborne droplets of the virus and can have serious and sometimes fatal complications, such as pneumonia and brain inflammation.
Young children are 99 per cent protected once they have two doses of the measles, mumps and rubella vaccine at 12 months and 18 months, and people born before 1966 are considered to have natural immunity. But unvaccinated people, and those born since 1966 who had only one dose, are susceptible to the virus.
Dr Choong said it was frustrating that some of the recent cases of measles were in children whose parents refused to have them vaccinated.
He said WA already had rates of immunisation that were too low, and he now worried that the Federal Government's planned GP co-payment would worsen the situation.
"I'm very concerned because across Australia one of the things that is usually bulk-billed is immunisation, because it is the biggest public health initiative outside clean water and if we have a co-payment, we run the risk of driving down immunisation rates," he said. "That's why the AMA is calling on the Government to exclude immunisations from any new charges."