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UK health authorities say they are urgently investigating a rare discovery of polio virus in London’s wastewater samples, which could jeopardize UK polio-free status for the first time in almost two years. decades.
Several samples of waste from Beckton’s wastewater treatment plant in Newham, east London, tested positive for the vaccine-derived polio virus between February and May, the Security Agency said on Wednesday. UK Health.
Since then, the virus has continued to evolve and is now classified as a “vaccine-derived” type 2 polio virus, the UKHSA said, adding that it seeks to establish whether any community transmission is occurring.
The agency has declared a national incident and reported the situation to the World Health Organization.
“We are urgently investigating to better understand the scope 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, a consultant epidemiologist at the UKHSA. , he said Wednesday.
Poliomyelitis is a rare virus that can occasionally cause serious illness, such as paralysis, in people who are not fully vaccinated. The disease was previously common in the United Kingdom in the 1950s, but the country was declared free of polio in 2003.
The UKHSA said the risk to the general public is extremely low, but urged parents to make sure their children have been fully immunized against the disease. It is common practice in the UK for children to receive an inactivated polio vaccine as part of their routine vaccination program; with three shots before the age of one year and another shot at three and 14 years old.
“The majority of the UK population will be protected from childhood vaccination, but in some communities with low vaccine coverage, people may continue to be at risk,” Saliba said.
Every year, between one and three “vaccine-like” polio viruses are commonly detected in the British sewer system.
These detections have always been timely findings and have occurred earlier when a person vaccinated abroad with the live oral polio vaccine returned or traveled to the UK and briefly “vacated” traces of the vaccine-like polio virus. in their feces.
However, this is the first time that a group of genetically linked samples has been repeatedly identified for several months.
Scientists say this suggests that there has been some dispersal of the community among individuals closely linked to north and east London.
To date, the virus has only been detected in wastewater samples and no associated cases of paralysis have been reported, according to the UKHSA.
Although polio vaccination is common in the UK, immunization rates vary across the country, with communities with lower absorption at higher risk.
Vaccine coverage for childhood vaccines, in particular, has declined nationally and especially in parts of London in recent years.
The UK National Health Service said parents should contact their doctor’s surgery to check that their children’s vaccines are up to date.
“Most Londoners are fully protected against polio and will not have to take any further action, but the NHS will start contacting parents of children under the age of 5 in London who are not up to date with their polio vaccines. invite them. to protect themselves, “said Jane Clegg, NHS chief nurse in London.
“In the meantime, parents can also check their child’s vaccination status on their Red Book and people should contact their GP to book a vaccine if they or their child are not fully up to date.” added.
In 2004, Britain switched from an oral polio vaccine to an inactivated polio vaccine, which is given by injection and prevents infection.
In general, those infected with polio have no symptoms, although some may develop a flu-like illness up to three weeks later. In rare cases, the virus can attack the nerves in the spine and the base of the brain, which can lead to paralysis. It can sometimes attack the muscles used to breathe, which can be fatal.
Medical professionals said early detection of the virus would be important in controlling its spread and preventing more serious cases.
“In populations with low vaccine absorption, it is possible that the live polio vaccine may be spread from one person to another. If this is maintained, over time (one or two years) this vaccine-derived virus may mutate to become completely virulent and can start. cause paralysis in people who have not been vaccinated, “said Paul Hunter, a professor of medicine at the University of East Anglia.