Multiple sewage samples collected from the London Beckton Sewage Treatment Works between February and June 2022 were found to contain vaccine-like type 2 poliovirus (PV2).
This sewage treatment plant serves a large catchment area in North and East London, with a population of nearly 4 million people.
Virus evolution has occurred during this time period.
Because the virus isolated in the most recent samples had 6 and 7 VP1 nucleotide changes from the Sabin 2 vaccine strain, it is now classified as a vaccine-derived poliovirus (VDPV2).
In recent years, 1 to 3 poliovirus isolates per year have been detected in UK sewage samples. However, these have all been isolated detections unrelated to one another. The isolates discovered between February and June 2022 are genetically related in this case. This has prompted the need to investigate the extent of this virus’s transmission in Northeast London.
The most likely scenario is that a recently immunised person entered the UK before February 2022 from a country where oral polio vaccine (OPV) was used for supplementary immunisation campaigns. While the United Kingdom discontinued the use of OPV in 2004, several countries, including Pakistan, Afghanistan, and Nigeria, have continued to use OPV containing type 2 virus for outbreak control.
As part of national polio surveillance, health professionals are now strongly encouraged to thoroughly investigate and report any suspected cases of acute flaccid paralysis / acute flaccid myelitis (AFP/AFM) that cannot be explained by a non-infectious cause.
Acute flaccid paralysis/myelitis is distinguished by the rapid onset of weakness in an individual’s extremities, which frequently includes weakness of the muscles of respiration and swallowing, and progresses to maximum severity within 10 days. The term ‘flaccid’ refers to weakness in the affected limb that is accompanied by hyporeflexia or areflexia (s).
Polio has no cure, but there are treatments. The emphasis of modern treatment has been on symptom relief, hastening recovery, and avoiding complications. Antibiotics to prevent infections in weakened muscles, analgesics for pain, moderate exercise, and a nutritious diet are all supportive measures.
In 2002, Europe was declared polio-free. WHO confirmed two cases of circulating vaccine-derived poliovirus type 1 in Ukraine on September 1, 2015.
The majority of people infected with poliovirus do not exhibit any symptoms. When symptoms do appear, they can range from a fever to paralysis.
Fever and fatigue are common initial symptoms.
headache
vomiting
stiffness in the neck and limb pain
