Enlarge / Transmission electron micrograph of poliovirus type 1. (credit: Getty | BSIP)

An eradicated form of wild polio surfaced in routine wastewater monitoring in the Netherlands last year, offering a cautionary tale on the importance of monitoring for the tenacious virus, researchers report this week in the journal Eurosurveilance.

The sewage sample came up positive for infectious poliovirus in mid-November and genome sequencing revealed a strain of wild poliovirus type 3, which was declared globally eradicated in 2019. Its potential revival would be a devastating setback in the decades-long effort to stamp out highly infectious and potentially paralytic germ for good.

For brief background, there are three types of wild polioviruses: type 2 and type 3 have been eradicated, with the former being knocked out in 2015. Wild poliovirus type 1 continues to circulate in Afghanistan and Pakistan. There are also occasional vaccine-derived polioviruses that circulate in communities with low vaccination rates, which recently occurred in New York.