British health authorities have said they are “urgently” investigating the discovery of a rare poliovirus in sewage samples in London.
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British health authorities have said they are urgently investigating a rare finding of polio virus in sewage samples in London, potentially jeopardizing Britain’s polio-free status for the first time in nearly two decades.
A number of waste samples from the Beckton sewage treatment plant in Newham, east London, tested positive for the vaccine-derived polio virus between February and May, it was announced on Wednesday the UK Health Security Agency.
The virus has since continued to evolve and is now classified as a type 2 “vaccine-derived” polio virus, the UKHSA said, adding that it was looking to establish whether community transmission was occurring.
The agency declared a national incident and notified the World Health Organization of the situation.
“We are urgently investigating to better understand the extent of this transmission and the NHS has been asked to promptly report any suspected cases to the UKHSA, although no cases have been reported or confirmed so far,” said Dr Vanessa Saliba, consultant epidemiologist at UKHSA. , said Wednesday.
Poliomyelitis is a rare virus that can sometimes cause serious illness, such as paralysis, in people who are not fully vaccinated. The disease was previously common in the UK in the 1950s, but the country was declared polio-free in 2003.
The UKHSA said the risk to the general public is extremely low, but urged parents to ensure their children have been fully immunized against the disease. It is common in the UK for children to receive inactivated polio vaccine as part of their routine immunization programme; with three blows given before the age of one and another blow given at three and 14 years old.
“Most of the UK population will be protected from childhood vaccination, but in some communities with low vaccination coverage individuals may remain at risk,” Saliba said.
Every year, it is usual for one to three “vaccine-like” polio viruses to be detected in the UK sewage system.
Such detections have always been one-time finds and have happened before when someone vaccinated abroad with the live oral polio vaccine returned or traveled to the UK and briefly ‘shed’ traces of the virus vaccine-like polio in his stool.
However, this is the first time that a group of genetically related samples has been repeatedly identified over several months.
Scientists say this suggests there has been some community spread between closely related individuals in north and east London.
So far, the virus has only been detected in sewage samples, and no associated cases of paralysis have been reported, according to the UKHSA.
While polio vaccination is common in the UK, vaccination rates vary across the country, with communities with low vaccination rates being more at risk.
Immunization coverage for childhood vaccines, in particular, has declined nationally and particularly in parts of London over the past few years.
The UK’s National Health Service has said parents should contact their doctor’s office to check that their child’s vaccinations are up to date.
“The majority of Londoners are fully protected against polio and will not need to take any further action, but the NHS will start contacting parents of children under 5 in London who are not up to date with their polio vaccinations to urge them to be protected,” said Jane Clegg, NHS chief nurse in London.
“In the meantime, parents can also check their child’s vaccination status in their red book and people should contact their GP to book a vaccination, if they or their child are not fully up to date,” he said. -she adds.
In 2004 Britain switched from an oral polio vaccine to an inactivated polio vaccine, which is given by injection and prevents infection.
Typically, those infected with poliomyelitis have no symptoms, although some may develop flu-like illness up to three weeks later. In rarer cases, the virus can attack nerves in the spine and base of the brain, potentially leading to paralysis. Occasionally it can attack the muscles used for breathing, which can be fatal.
Health professionals said early detection of the virus would be important to monitor its spread and prevent more serious cases.
“In populations with low vaccination rates, there is potential for the live polio vaccine to spread from person to person. If this continues, over time (one or two years), this vaccine-derived virus may mutate to become fully virulent again and can begin to cause paralysis in people who have not been vaccinated,” said Paul Hunter, professor of medicine at the University of East Anglia.