In an announcement made on Wednesday, the UK Health Safety Agency (UKHSA) said that polio was identified in sewage samples collected in London between February and May 2022.
The agency said it was “likely” that the virus was spreading between “closely linked” individuals in northeast London, and an investigation had been launched to establish whether any community transmission was taking place.
Thanks to extensive vaccination efforts around the world, the disease has largely been eliminated. Afghanistan and Pakistan are the only two remaining countries in the world where polio is still classified as endemic.
What type of polio was found?
Analysis shows that the virus picked up by UKHSA is not ‘wild type’ polio. Instead, it is a version of the virus that derives from the live oral polio vaccine (OPV).
This vaccine generates intestinal immunity and for several weeks after vaccination, people can shed the vaccine virus in their stool.
These vaccine viruses can spread in undervaccinated communities from person to person through poor hand hygiene and contamination of water and food. Coughing and sneezing, although less common, is another route of transmission.
What are the symptoms of polio?
According to the NHS, most people who get polio have no symptoms.
However, some may have mild flu-like symptoms lasting ten days, such as:
- a high temperature
- extreme tiredness (fatigue)
- be sick (vomit)
- a stiff neck
- muscle pain
In rare cases, polio can cause temporary difficulty using muscles, usually in the legs. This can happen over hours or days.
Long-term complications of polio can include paralysis and some long-term treatment needs for muscle weakness, joint problems, or swallowing difficulties.
Treatments for polio include:
- hospital rest
- help with breathing
- regular stretching and exercise to prevent problems with your muscles and joints