Detection of Wild Poliovirus in Hamburg, Germany

Germany public health monitors sewage for polio viruses. This has been in place since 2021. During October 2025, poliovirus type 1 was identified in Hamburg sewage. This is the wild virus and not one which is vaccine associated.

Genetic sequencing of the virus determined it came from Afghanistan. The wild type virus is only found in Afghanistan and Pakistan.

Environmental detection, not a human case

It is important to understand that the report is not about a case of polio, just the presence of the virus in the environment. It would have been excreted by an asymptomatic carrier of the virus. More than 75% of people infected with the poliovirus will be asymptomatic.

The concern from a public health aspect is for the virus to be transmitted to a non-immune individual and for them to become symptomatic. In a country like Germany or Australia, most of the population have been vaccinated and the virus has nowhere to go. The public health infrastructure is also good in high income countries, so wastewater is treated very well.

Risk when carriers travel to low immunisation countries

If the carrier of the virus was to travel to a country with low immunization levels, then there is every possibility for many non-immune people to be infected and cases of paralytic polio to be reported. Notifications of the wild type virus are rare.

Europe was declared polio free in 2002 with the last case of polio occurring in Germany in 1990.

Vaccine-Derived Poliovirus in Europe

Vaccine-derived polio notifications are more common.

Several European countries including the United Kingdom have reported vaccine derived polio in wastewater in the last few years. The most recent report was in September this year with polio virus type 2 being detected in Yorkshire. The detection of poliovirus type 2 (VDPV2) in London sewage in February, 2022 prompted an extra booster dose of polio being recommended for year 9 children in London.

Vaccine-Derived Polio in PNG

Vaccine derived polio virus has recently (2025) been detected in PNG. This has led to human cases, including paralysis. See - Circulating vaccine-derived poliovirus type 2 (cVDPV2) - Papua New Guinea

How does vaccine-derived Poliovirus emerge?

Vaccine-derived poliovirus develops from the weakened strain of the live virus found in the polio vaccine. If it is allowed to circulate in poorly immunized populations, there is a possibility it can change to a more serious form of the disease and cause clinical paralytic polio (vaccine-associated paralytic polio).

This has occurred in many regions of the world where the oral polio vaccine is being used. It happened in Gaza in 2024. The Gaza war resulted in a fall in immunization rates and provided optimum conditions for an outbreak of polio in the community - see Polio Returns to Gaza after 25 years. Immunisation coverage for the second dose of polio fell from 99% in 2022 to less than 90% in the first quarter of 2024.

It is well recognized that levels above 95% are required to reduce the risk of re-emergence of this old scourge.

History of Polio Vaccination in Australia

The Salk inactivated polio vaccination became available in Australia in 1955. Major epidemics were occurring at the time. A large percentage of the population was vaccinated during the 1950’s. The live attenuated Sabin vaccine was later registered in 1964.

In 1966 this vaccine was then recommended for everyone, irrespective of vaccination. The course was 3 doses. It was nationally funded for all infants in 1975. It is likely many individuals born in the 1950’s have had courses of both vaccines.

The inactivated polio vaccine was recommended to replace the live vaccine in 2003, but it took a couple of years before it was fully implemented.

Polio is a notifiable disease in Australia. Australia was declared polio free in 2000.

In 2020 the IPV coverage was over 95%.

The last case reported in Australia was in 2007, where the individual contracted the infection in Pakistan.

Polio risk to travellers.

The risk of exposure to polio for most travellers is very low.

This presumes that most travellers are fully vaccinated. We know that 95% children who are born in Australia receive their childhood vaccinations. An unvaccinated individual might be protected in Australia but not when travelling.

The risk of international exposure to the wild virus is very low with only 2 countries reporting cases in the last 12 months (Afghanistan, Pakistan). The main concern for travellers is the potential exposure to the vaccine derived poliovirus.

The Global Polio Eradication Initiative (GPEI) provides a dashboard for countries reporting both cases and positive environmental samples see: Global circulating vaccine-derived (cVDPV) - AFP cases and environmental samples 2021 - 2025

Most high-risk countries have poor public health infrastructures where safe water cannot be assured.

An adult polio booster (IPOL) might be offered to those intending to visit these countries if they have not had a booster in the last 10 years. This group includes long-term expatriate workers, international volunteers working in NGO’s and those intending basic travel with high-level community exposure.

The risk of travellers to high income countries reporting polio in wastewater would be low, however frequent travellers might be offered polio as a combo with the triple antigen if indicated. Two are available in Australia (Boostrix IPV, Adacel polio).

Find out more about polio vaccination.