On Wednesday, the UK Healthcare Agency (UKHSA) announced the detection of a vaccine-derived polio virus in sewers in north and east London in February, saying it was spreading between individuals. Authorities did not report any new cases, but urged people to get vaccinated.
It was last spotted in the UK in 1984 and destroyed in 2003.
London has one of the worst rates of polio vaccination in the world, with one-third of children not getting the first vaccine at 12 months and almost a quarter at 24 months not getting vaccinated. Although vaccines are usually given to children, about one in 10 do not get vaccinated and do not increase by 30% in adolescence.
In people who have not been vaccinated, the disease can lead to rare but serious complications. It affects the spinal cord and the base of the brain, causing strokes, usually developing in the legs, hours or days. If the respiratory muscles are affected, it can be life threatening. Authorities are concerned that even those who have been fully vaccinated may catch the virus without even knowing it.
The disease is spread by poor hand hygiene and, less commonly, by coughing and sneezing. The virus multiplies in the gut and infected people excrete large amounts of the virus in their feces.
Experts believe the virus may have been imported from someone who recently received the oral polio vaccine in another country, in which the live virus spills into the feces and enters London’s sewage system. This strain was discovered during the government’s ongoing inspection of sewage.
“There is potential for the spread of vaccine-derived poliovirus, especially in communities where vaccination is low,” said Vanessa Saliba, a UKHSA consultant epidemiologist. “We are urgently investigating the extent of this exchange and are urging the NHS to report any suspicious cases to the UKHSA expeditiously.”
Nearly two years ago, countries in Africa declared themselves polio-free, making Afghanistan and Pakistan the only countries in the world still to have polio. The $ 1 billion public-private partnership is being implemented from 2021 and aims to end the disease once and for all in the world by 2026.
