Poliovirus detected in wastewater in Australia

The Australian Centre for Disease Control (CDC) has announced that vaccine-derived poliovirus was detected in wastewater in Australia during routine surveillance of untreated sewage at a treatment plant in Perth. 

Early assessments suggest the detection is most likely linked to a person who recently arrived from overseas, as there are currently no known cases of polio and the oral polio vaccine is not used in Australia. 

This detection reinforces the effectiveness of Australia’s disease surveillance and monitoring systems.
 

About polioviruses

Polio is a highly contagious viral infection that spreads from one person to another through food, water or items contaminated with the faeces of an infected person. Most infected people have no or mild symptoms that resolve within 1–2 weeks, but in a small proportion of cases (<1 in 100), infection can lead to paralysis and, rarely, death. 

There are 3 types of naturally occurring (‘wild’) poliovirus – types 1, 2 and 3. Circulating vaccine-derived polioviruses (cVDPV) originate from oral polio vaccine (OPV), which contains a weakened live attenuated virus. Although rare, cVDPV outbreaks can occur in under-immunised populations.
 

Surveillance in Australia

Polio surveillance in Australia uses multiple detection systems, including:

• clinical surveillance for acute flaccid paralysis (AFP) in children less than 15 years of age
• laboratory testing of stool samples
• environmental surveillance through wastewater monitoring.

The Paediatric Active Enhanced Disease Surveillance (PAEDS) system, hosted by NCIRS, has conducted hospital-based surveillance for AFP since 2007. It is a key partner of Australia’s polio surveillance program, helping ensure Australia retains its polio-free status. 

Polio remains a notifiable disease in Australia, with laboratory-confirmed cases reported to the National Notifiable Disease Surveillance System.
 

What this means for Australians

The strain detected in Western Australia is vaccine-derived poliovirus type 2, which is found in parts of the world where the OPV is used and where low immunisation coverage and poor sanitation allow for easy transmission. 

Only inactivated poliovirus (IPV)-containing vaccine is used in Australia.

While Australia remains polio-free and vaccination coverage is high, the Australian CDC continues to advise people to check they are up to date with routine vaccinations, including polio. 

Polio vaccination is part of the routine childhood immunisation schedule and is free under the National Immunisation Program for children aged 2 months, 4 months, 6 months and 4 years. Free catch-up vaccination is also available for eligible people under 20 years, and refugees and other humanitarian entrants of any age. 

IPV vaccines used in Australia are safe and very effective, protecting against all 3 types of polioviruses, and cannot cause cVDPV as it is not a live vaccine.