Public health responses following identification of poliovirus in wastewater.

Poliovirus continues to pose a global public health threat, with both wild and vaccine-derived viruses detected in clinical and environmental samples, including in countries declared to be polio free. Although wastewater and environmental surveillance increasingly reveal silent poliovirus circulation, how these findings are translated into public health action remains unclear. We reviewed the literature to identify documented events in which poliovirus detection in wastewater triggered public health responses across WHO regions. 26 unique events across 21 countries and all six WHO regions were included. Public health actions were analysed across five response domains defined for this Review: environmental surveillance; clinical surveillance; vaccination; risk communication; and coordination. Across diverse epidemiological contexts, poliovirus detection in wastewater consistently prompted public health action, often in the absence of paralytic cases. Enhanced environmental surveillance was the most common response, frequently accompanied by intensified clinical surveillance and targeted vaccination activities. Overall, our Review highlights environmental surveillance as an operational early warning system within the Global Polio Eradication Initiative and provide insights applicable to preparedness and response frameworks beyond poliovirus.