The British health authorities announced Wednesday that a poliovirus detection in London's sewage water prompted them to declare a national crisis.

In collaboration with the Medicines and Healthcare products Regulatory Agency (MHRA), the UK Health Security Agency (UKHSA) discovered poliovirus in sewage samples taken from the London Beckton Sewage Treatment Works, according to a government release.

The finding of the virus VDPV2 "suggests that there has likely been some spread between closely related individuals in North and East London, and that these individuals are now shedding the type 2 poliovirus strain in their feces."

"The virus has only been detected in sewage samples, and no paralysis cases have been reported; however, investigations will seek to determine if there is any community transmission."

In 1984, the last case of wild polio caught in the United Kingdom was confirmed. In 2003, the UK was proclaimed free of polio.

Parents have been asked to check their child's immunization status and to call their primary care physician if they or their child are not fully vaccinated.