Poliovirus strain detected in WA for the first time

A strain of poliovirus has been detected at a wastewater treatment facility in Western Australia, with authorities now on high alert and monitoring the situation.

The Australian Centre for Disease Control is working closely with the state government, the National Polio Surveillance Program and expert advisory groups to assess the finding and coordinate any necessary response to the detection at the Subiaco wastewater treatment plant.

It has been identified as vaccine-derived poliovirus, which is rare but can occur in parts of the world where the oral polio vaccine is still used, meaning it is likely from someone who has lived overseas and travelled to Perth.

This is the first time the strain has been detected in Australia, which does not use the oral vaccine.

Similar detections have occurred in other countries, including in Europe in 2024 and 2025, without leading to cases of polio.

WA’s Chief Health Officer, Dr Clare Huppatz, said the detection was of very low risk to the population.

“While this is a significant finding, this detection does not provide evidence of spread of the disease in WA,” she said.

Australia was declared free from polio in 2000. This incident does not affect that status.

Australian Centre for Disease Control director general, professor Zoe Wainer, said the detection showed disease surveillance and monitoring systems were working.

“Wastewater surveillance is designed to give us early warning, so health authorities can take precautionary action,” Wainer said.

“This is an environmental detection, not a clinical case. No cases of polio have been identified, and there is no evidence of local transmission.”

Australian National University infectious diseases specialist and associate professor of medicine Sanjaya Senanayake said Poliovirus at its worst can cause paralysis and death, especially in children.

“Global vaccination programs over many decades have almost eradicated it, but we are not quite there,” he said.

“Outbreaks of polio in our region have been few and far between, although they have occurred in the Philippines, Indonesia and PNG.”

Senanayake said there were two ways to contract polio – through infection with mutated forms of virus derived from the oral polio vaccine like the case detected, or through the “natural” circulating virus which still occurs in Pakistan and Afghanistan, where there have been challenges with vaccination programs.

Flinders University epidemiologist associate professor Jacqueline Stephens said WA had very high childhood vaccination coverage at around 92 per cent.

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