German health authorities have detected the wild poliovirus type 1 (WPV1) in a wastewater sample from Hamburg, marking the frist instance of the virus being found in German sewage since monitoring began in 2021. [[1]] While no cases have been reported, the revelation-detailed in the Robert Koch Institute’s November bulletin-signals the potential for renewed vigilance against a disease largely eradicated through vaccination. The findings come amid ongoing detection of circulating vaccine-derived poliovirus type 2 in europe and underscore the importance of maintaining high immunization rates.
German health officials have detected the wild poliovirus type 1 (WPV1) in a wastewater sample collected in Hamburg, according to a recent report from the Robert Koch Institute (RKI), Germany’s national public health institute. The sample, collected on October 6, 2025, was analyzed as part of the RKI’s ongoing research project to monitor for polioviruses in wastewater (PIA).
This discovery, detailed in the November 2025 issue of the RKI’s Epidemiological Bulletin, is unusual but not entirely unexpected, researchers say. While WPV1 currently circulates only in Afghanistan and Pakistan, it has been detected in environmental samples in Iran (2019) and confirmed in cases in Malawi (2021) and Mozambique (2022). The detection of the virus in wastewater suggests that at least one individual in Hamburg shed the virus around the time the sample was taken.
Notably, no clinical cases or suspected cases of polio have been reported to the RKI to date. Germany has not seen a case of wild poliovirus contracted within the country since 1990, and the last imported cases were recorded in 1992. Regular wastewater testing for polioviruses began in Germany in May 2021, a collaborative effort between the RKI and the German Environment Agency (UBA). Prior to this, WPV1 had not been identified in German wastewater samples.
The RKI bulletin clarifies that this finding is unrelated to circulating vaccine-derived poliovirus type 2 (cVDPV2), which has been detected in wastewater in Germany and other European countries since late 2024. However, both cVDPV2 and WPV1 can cause polio in individuals who are unvaccinated or incompletely vaccinated. Full vaccination against polio with the inactivated polio vaccine (IPV), which is used in Germany, provides reliable protection against the disease, though limited protection against infection and further transmission of the pathogen.
Infected individuals can potentially spread the virus through direct contact and contaminated surfaces, particularly via fecal matter in settings with poor hygiene. Initial transmission can also occur through respiratory droplets, such as from coughing or sneezing. This finding underscores the importance of maintaining high vaccination rates to prevent the re-emergence of polio, a disease once considered nearly eradicated thanks to widespread vaccination efforts.
The detection of WPV1 in Germany raises questions about the potential for the virus to resurface in regions with declining immunity. Experts are closely monitoring the situation to assess the risk and implement appropriate public health measures.
The issue will be discussed this evening on Idei în nocturnă. Diaspora. Dincolo de granițe, featuring Dr. Evelina Moraru, professor emerit, UMF “Grigore T. POPA Iași, and pediatrician; Prof. univ. dr. Doina Azoicai, doctor in medical sciences and head of the Epidemiology Discipline at UMF Iași; and Dr. Cristian Apetrei, dr. in microbiology and Professor of Infectious Diseases and Microbiology at the University of Pittsburgh, USA.
Idei în nocturnă. Diaspora. Dincolo de granițe, on Radio România Cultural and at www.radioromaniacultural.ro, from 9:10 PM to 10:00 PM, with Corina Negrea.
