The national polio surveillance program has detected poliovirus in a wastewater sample taken from a wastewater catchment in Perth in mid-April 2026.
The surveillance system monitors wastewater for poliovirus and serves to provide an early warning on presence of the poliovirus in Australia.
The wastewater detection demonstrated evidence of a vaccine derived poliovirus Type 2 strain, similar to what has been detected in the wastewater of various countries globally in recent years, including in Africa, Europe and Papua New Guina.
Western Australia's Chief Health Officer, Dr Clare Huppatz, said this single wastewater polio detection event was of very low risk to the population.
"The potential for this strain to circulate in a highly vaccinated population is very low, and the poliovirus vaccination coverage in WA children is 92 per cent," Dr Huppatz said.
"While this is a significant finding, this detection does not provide evidence of spread of the disease in WA."
The presence of the virus in wastewater in Europe during 2024 and 2025 did not lead to anyone developing the disease.
"This finding is most likely from someone who has travelled overseas and is shedding this virus strain," she said.
"Fortunately, Australia has an excellent vaccination program against poliovirus which will protect the community against this strain.
"This does however serve as a timely reminder that poliovirus continues to circulate in other countries, and the importance of making sure you and your family are fully vaccinated."
Many overseas countries use the oral polio vaccine which contains a small amount of live, but weakened, virus. Rarely, the virus in the oral polio vaccine can evolve to create a vaccine derived poliovirus strain, which can be transmitted among communities with low vaccination coverage.
Australia uses inactivated polio vaccines which do not contain live virus and are given by injection.
Thanks to vaccination, poliovirus has been eliminated from Australia since 2000.
Most people with poliovirus infection have no or mild symptoms, however a very small number of cases can progress to paralysis which includes severe muscle pain, weakness and involuntary movements.
In response to this detection, the WA Department of Health is increasing the frequency of wastewater poliovirus testing in the Perth metropolitan area and working with clinicians to enhance existing systems for detecting polio in WA hospitals.
Under the National Poliovirus Response Plan, the Australian Centre for Disease Control reported the finding to the World Health Organization.
"The WA Department of Health is working closely with the Australian Centre for Disease Control and will continue to monitor the situation," Dr Huppatz said.
Vaccination status can be checked by accessing immunisation records on MyGov or through immunisation providers.
Free polio vaccine is available under the National Immunisation Program for children aged 2, 4, 6 months and 4 years, people under 20 years who are eligible for catch-up vaccination and refugees and humanitarian entrants of any age.
To book a vaccination, people are encouraged to contact their GP, pharmacist for those aged 5 years or over, or other immunisation provider. Immunisation providers can be located via the WA Health website. Consultation fees may apply.
