In case you haven’t had enough of awful viruses yet in 2022, it seems that polio is back in the US, at least in New York.

Polio has no known cure. Whilst most infected people don’t develop noticable symptoms, it can cause outcomes as harmful as paralysis in some patients, a fraction of which may die due to paralysis of their breathing muscles. It was once known as infantile paralysis, due to children’s heightened vulnerability to the disease.

Only one human case had been detected as of four days ago, but it’s been seen in the city’s wastewater and become enough of an issue that the mayor declared a state of emergency. The CDC has confirmed that the US should now be considered a country with circulating poliovirus again, after 43 years of polio-free status.

One driving factor is likely the fact that polio vaccination rates are really not very high in some places any more, as shown in this map from the City of New York’s website. Nearly half of Williamsburg’s young children haven’t been fully vaccinated.

Over here in the UK we’re hardly immune - polio has been detected in our sewage too, although we don’t seem to have found any reported transmission within the community. It’s also been spotted in many countries within Africa this year.