Western Australia's Chief Health Officer Clare Huppatz has confirmed that poliovirus has been detected in Perth's wastewater, marking the first such finding in Australia in almost two decades. The highly contagious virus, which can cause paralysis in severe cases, was identified in a sample taken from the Subiaco Wastewater Treatment Plant in mid-April.
Vaccine-derived strain found
WA Health reported that the detected strain is a vaccine-derived Type 2 poliovirus, which has previously been found in parts of Africa, Europe, and Papua New Guinea. The discovery was made by the National Laboratory in Melbourne, which then notified WA Health. The Centers for Disease Control and Prevention in the United States were also consulted on the response.
"This is the first time that we've had a detection like this in Perth," Dr Huppatz said. "We really wouldn't know where this has come from in terms of the person that might have been involved with this."
Possible link to overseas travel
Authorities believe the virus likely came from a person who traveled from a region where oral polio vaccines are used. "When you've been exposed, you can shed for quite some time, and they've probably come back to Australia after shedding. It's very possible that they have also left," Dr Huppatz added.
Testing at the Subiaco treatment plant and two nearby sites will be increased to weekly testing for the next six months. The virus is primarily spread through the fecal-oral route, where infected fecal matter is ingested. Most people infected do not show symptoms, but in rare cases, it can cause paralysis or death.
No outbreak expected
Dr Huppatz noted that similar detections in other countries, including across Europe, have not led to outbreaks. "It is a timely reminder that polio virus is still circulating around the world. And of course, with international travel, it is something that people could be exposed to, even in Perth," she said.
She emphasized that vaccination is the best protection. "The best way to ensure that you're protected is to be vaccinated. Poliovirus is one of the vaccinations in the normal routine childhood vaccination campaign. So I would just really encourage all parents to make sure their children are up to date with their vaccinations, and if other people want to check their vaccination status, they can do that through MyGov or with their local doctor."
Experts urge vigilance
Curtin University Professor Jaya Dantas, from the school of population health, stressed the need for continued vigilance. "Polio continues to be of concern in Pakistan and Afghanistan where it is endemic," she said. "Whilst we have a great health system in WA and with the Australian CDC commencing and setting up its advisory council – we need to remain vigilant and ensure that our messaging about vaccination and its long-term benefits is consistent, strong and ongoing and be supportive of those most at risk."
