A wild form of polio was found in a German sewage sample. What does it mean?
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German officials on Thursday identified the northern city of Hamburg as the site where a sewage sample containing the wild form of the polio virus was found.
Wastewater at an unspecified German location tested positive for the wild poliovirus, the country’s main public health body, the Robert Koch Institute, or RKI, told Reuters on Wednesday, a blow to efforts to rid the world of the deadly disease.
The findings come more than 30 years after the last reported case of wild poliovirus infection in people in Germany and the first case of wild poliovirus being detected from an environmental sample in the country since such routine surveillance began in 2021.
Health officials in the city of Hamburg, one of Germany’s 16 regional states, said in a statement that they had convened an expert task force on infection control and would take more samples while coordinating closely with the RKI.
But no infections have been reported, and experts say the risk is limited, because vaccination against polio is widespread in Germany. Here’s what separates wild polio from other types, and what we can tell us from wastewater detection.
What is polio?
Polio, short for poliomyelitis, is an infectious disease that terrified parents around the world in the first half of the 20th century. It mainly affects children under five years of age, it is often symptomless but can also cause symptoms such as fever and vomiting.
About one in 200 infections results in irreversible paralysis, and up to 10 percent of those patients die. There is no cure, but it can be prevented by vaccination and the rate of cases globally has declined by 99 percent since mass vaccination efforts began in 1988.
What about wild polio?
There are two forms of polio: wild polio and vaccine-derived or variant polio. Both can cause paralysis and death, but wild polio is rare and is now endemic only in Afghanistan and Pakistan, causing tens of thousands of cases each year. The strain found in German wastewater is linked to the strain circulating in Afghanistan.
The vaccine-derived form of the virus is more common, although still rare. It causes several hundred cases globally each year, primarily in countries such as Yemen and Nigeria.
This form of polio results from the use of oral polio vaccine containing weakened live virus.
After children are vaccinated, the virus continues to be shed in their stool for a few weeks. In under-vaccinated communities, it could spread and mutate back into a harmful version of the virus. To reduce this risk, a new version of this vaccine is being introduced.
as it happens6:53Final phase of polio vaccination halted in northern Gaza due to dangerous conditions
UNICEF and the World Health Organization are working to give polio doses to 640,000 children in Gaza. But now, intense Israeli bombardment and large-scale population displacement in the north of the enclave have halted the final phase. UNICEF Palestine’s head of communications Jonathan Croix told As It Happens host Nils Koksal that more than 119,000 children in the north cannot be vaccinated under current circumstances.
While countries such as Germany no longer use the live polio vaccine, others – especially where polio is more widespread – do, because it prevents transmission.
What does this identity mean?
Many countries around the world sample sewage to track the spread of polio. Experts said Germany’s detection is a sign that the system is working well.
There have also been no reports of infections in Germany and scientists say high vaccination coverage reduces the risk.
Finding wild polio in the region is rare: It hasn’t happened in Europe since 2010, WHO said Wednesday, though that suggests not just that it was detected, but that it wasn’t there at all.
Other wild polio-free areas have recently detected it, or even seen outbreaks, when the virus was imported into different countries. For example, in 2022, Malawi and Mozambique experienced outbreaks, following years where cases of wild polio were reported in both countries, which was also linked to the strain spreading in Pakistan.
What does this mean for the rest of the world?
WHO and other partners, including the Gates Foundation, have been working with governments to eliminate polio for decades. But despite great progress, completing the work has proven challenging and expensive. The partnership, called the Global Polio Eradication Initiative, faces a 30 percent budget cut next year amid sweeping international aid cuts.
GPEI said it primarily serves as a reminder that the world must unite to complete the task of eliminating the disease.
Beate Kampmann, scientific director of the Center for Global Health at Charite in Berlin, Germany’s largest university hospital, said the findings also underlined the importance of vaccination.
“Polio anywhere means the potential risk of polio everywhere,” he told Reuters. He said continued funding is important for polio eradication.
Experts say anyone concerned about polio should check with their health care provider about their or their children’s vaccination status and make sure they have received a full dose.
