New York City and state health officials on Friday urged residents who haven’t been vaccinated against polio to do so, after the virus that causes the paralytic disease was detected in the largest US city’s sewage samples. The discovery comes just weeks after a confirmed case in a nearby county.

“likely local circulation of the virus.” Sewage samples from Rockland and Orange counties north of New York City also showed the presence of polio last month, followed by the discovery of the first domestic US polio infection since 1979.

“alarming, but not surprising,” and added that the state department of health is “responding urgently, continuing case investigation and aggressively assessing spread,” in cooperation with local and federal partners.

“Polio is entirely preventable and its reappearance should be a call to action for all of us,” Vasan said. Vaccine clinics will be popping up to offer the inactivated polio vaccine (IPV) to residents.

Sewage samples from Orange and Rockland were “genetically linked” to the confirmed Rockland polio case, the Centers for Disease Control and Prevention (CDC) said after running a sequencing analysis. The man developed symptoms that included weakness and muscle paralysis. 

“shedding” the weakened virus. British authorities blamed this phenomenon for the discovery of polio in London sewage samples in June.

“wild” polio have been eradicated across much of the world thanks to an aggressive vaccination campaign. The last remaining strain remains endemic in Afghanistan and Pakistan.