It’s “possible” to trace the source of the poliovirus detected in London to a house or street, a health secretary suggested.
A national incident was announced after the UK Health Safety Administration (UKHSA) found polio in sewage samples taken by the London Beckton Sewage Treatment Works, which serves about four million people in north and east London.
While it’s normal for viruses to be picked up as isolated cases and not rediscovered, experts have sounded the alarm after several genetically related viruses were discovered in samples between February and May.
Health Secretary Lord Kamall told colleagues on Thursday it was possible to pinpoint the source of the virus to a single address.
“It’s mixed up with a lot of stuff and what we need to try and figure out now is how we go through the pipes and examine each one to see if we can pinpoint the source,” Lord Kamall said.
“Theoretically, it is possible to find individual households and streets, but it is too early.
“What we’re doing here is absolutely world-leading, it’s a first and it shows we’re ahead, but one of the problems with moving forward is we’re discovering things that haven’t been discovered before.”
UKHSA is “immediately” investigating whether the virus can spread from person to person in the capital, which if confirmed would mark the UK’s first outbreak in decades.
The health agency is working on a theory that someone vaccinated abroad with the polio vaccine – possibly in Afghanistan, Pakistan or Nigeria – entered the UK in early 2022 and spread the virus.
The person may now have passed it on to other close associates in north-east London, who in turn passed the virus into their faeces.
The virus detected in sewage by UKHSA was not ‘wild-type’ polio, but a version of the virus derived from the live oral polio vaccine (OPV), which the UK stopped vaccinating in 2004.
OPV creates gut immunity, and people can shed vaccine-derived virus into their feces for several weeks after vaccination, which can then be spread in under-vaccinated communities through poor hand hygiene, contaminated water and food, and, in the case of less often, through coughing. and sneeze.
Lord Kamall stressed: “Nobody has had polio and no cases have been identified, we found them in the sewers.”
Health officials have urged the public to ensure they are fully immunized against the virus, which was declared eradicated in the UK in 2003 due to high vaccination rates, with the last wild case detected in 1984.
Labor’s Lord Reid of Cardowan has urged the Government to maintain “maximum transparency” on national incidents and questioned whether concerns about a Covid vaccine had led to a “considerable drop in vaccinations against other potential diseases”.
Recent figures show that in the UK nearly 95 per cent of children by the age of two have received the correct number of doses of the polio vaccine. However, in London this fell to almost 90 per cent.
Lord Kamall replied that the Government was “quite clear” that “people need to come forward for all vaccines”, adding: “What’s really important is that we recognize that vaccine-induced polio can spread, but it’s rare and the risks to society at large are limited.”
Health Minister Sajid Javid said this week he was “not too worried” about detection of the virus, which in rare cases can cause paralysis in people who are not vaccinated.
He told BBC Radio 4 that UKHSA “reminds me that as a country we have very high rates of polio immunization,” adding: “We have been declared polio-free since 2003 and there have been no cases since.”
Additional reporting by PA