First Polio Outbreak In 40 Years Feared As Virus Found

Health officials have declared a national incident as they investigate the scale of a feared polio outbreak following the discovery of the virus in wastewater.

- Samuel Lovett

The virus, which can cause paralysis in rare cases, was identified in sewage samples taken from London between February and May 2022, according to the UK Health Security Agency (UKHSA).

The UKHSA said it was "likely" there has been a spread of a vaccine-derived poliovirus type 2 (VDPV2) between closely linked people in northeast London, with infected individuals believed to be shedding the virus in their faeces. So far, no suspected cases have been reported or confirmed.

The agency is now "urgently" investigating whether wider transmission of the infection, which can spread without symptoms in low-vaccinated communities, is occurring in the capital. If confirmed, this would be the first outbreak of polio in the UK in nearly 40 years.

Dr Vanessa Saliba, a consultant epidemiologist at UKHSA, said: "Most of the UK population will be protected from vaccination in childhood, but in some communities with low vaccine coverage, individuals may remain at risk. We are urgently investigating to better understand the extent of this transmission and the NHS has been asked to swiftly report any suspected cases to the UKHSA, though no cases have been reported or confirmed so far."

The rise of VDPV2s throughout the globe is threatening attempts to eradicate polio. They are a rare, mutated version of the virus - typically found in under-immunised communities with poor sanitation - which derive from the live oral polio vaccine (OPV).