Poliovirus found in wastewater in Spain, Germany, and Poland Premium

Global polio eradication efforts, vaccine-derived strains, and the importance of vaccination coverage highlighted in a comprehensive overview.

In 1988, the World Health Organization (WHO) called for the global eradication of polio. Within a decade, one of the three poliovirus strains was already virtually eradicated — meaning a permanent reduction of the disease to zero new cases worldwide.

Polio, also known as poliomyelitis, is an extremely contagious disease caused by the poliovirus. It attacks the nervous system and can lead to full paralysis within hours. The virus enters through the mouth and multiplies in the intestine. Infected people shed poliovirus into the environment by the faecal-oral route.

About one in every 200 infections results in irreversible paralysis (usually affecting the legs). Of those who become paralysed, 5–10% die due to immobilised breathing muscles.

Since 1988, the global number of poliovirus cases has decreased by over 99%. Today, only two countries — Pakistan and Afghanistan — are considered “endemic” for polio. This means that the disease is regularly transmitted in the country.

Yet in recent months, poliovirus has been detected in wastewater in Germany, Spain and Poland. This discovery does not confirm infections in the population, but it is a wake-up call for Europe, which was declared polio free in 2002. Any gaps in vaccination coverage could see a resurgence of the disease.

Poliovirus strains originating from regions where the virus remained in circulation led to outbreaks among unvaccinated people in Tajikistan and Ukraine in 2021, and Israel in 2022. By contrast, in the UK — where poliovirus was detected in wastewater in 2022 — no cases of paralytic disease were recorded.

This information highlights the varied effect of poliovirus detection. Why? In areas with under-immunised populations, the virus can circulate widely and cause paralysis. But in communities with strong vaccination coverage, the virus often remains limited to symptomless (“asymptomatic”) infections or is detectable only in wastewater.