A strain of polio has been detected in a wastewater sample in Perth, sparking concerns that the deadly disease might have returned to Australia 26 years after it was declared eliminated. Polio is a highly contagious infection caused by the poliovirus, which can lead to long-term disability, paralysis, and death. There is no cure for the illness, but it can be prevented through vaccination.
Background on Polio in Australia
Australia has been polio-free since 2000, with the last locally acquired case recorded decades earlier in 1972. However, on Friday, the Western Australian Government's Department of Health reported that its surveillance program had detected poliovirus in a wastewater sample taken from a catchment in Perth in mid-April. This monitoring system is designed to provide early warnings of potential outbreaks.
Details of the Detection
Evidence was found of a vaccine-derived poliovirus Type 2 strain, similar to what has been detected in various countries over the last few years, including in Africa, Europe, and Papua New Guinea. While polio is a serious virus, WA's Chief Health Officer Dr. Clare Huppatz stated that the single detection poses a very low risk to the public.
"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," she said. "While this is a significant finding, this detection does not provide evidence of spread of the disease in WA."
Dr. Huppatz added that 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. 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."
Global Context and Vaccination
Before vaccines were introduced, polio was a major cause of death and disability. Thanks to global eradication efforts, annual cases have declined by over 99 per cent since the 1980s. Although the risk of polio in Australia is low, health authorities recommend vaccination, as outbreaks sometimes occur in neighbouring countries.
Most people with poliovirus infection have no or mild symptoms. However, a very small number of cases can progress to paralysis, which may involve severe muscle pain, weakness, and involuntary movements.
Health Authority Response
The WA Department of Health said it is increasing wastewater testing across metropolitan areas and working with clinicians to improve systems detecting possible polio cases in hospitals. Free polio vaccines are available under the National Immunisation Program for children, eligible people under 20, and refugees and humanitarian entrants of any age.
