UK health authorities have said they are ‘urgently’ investigating the discovery of a rare poliovirus in sewage samples in London.
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UK health authorities have said they are urgently investigating the discovery of a rare polio virus in sewage samples in London, potentially jeopardizing the country’s polio-free status for the first time in nearly two decades.
Several waste samples from the Beckton sewage treatment plant in Newham, east London tested positive for vaccine-derived polio virus between February and May. The UK Health Security Agency announced this on Wednesday.
Since then, the virus has continued to evolve and is currently classified as vaccine-derived type 2 poliovirus, the UKHSA said, adding that it is looking to establish if any community transmission of the virus is taking place.
The agency declared a national incident and informed the World Health Organization of the situation.
“We are urgently investigating to better understand the extent of this transmission and the National Health Service has been asked to promptly report all suspected cases to the UKHSA, although no cases have been reported or confirmed so far,” the doctor said. Vanessa Saliba, consultant epidemiologist of the UKHSA, said this on Wednesday.
Polio is a rare virus that can sometimes cause serious illness, such as paralysis, in people who have not been 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 are fully immunized against the disease. In the United Kingdom, it is common practice to administer inactivated polio vaccine to children as part of their routine vaccination program; with three vaccinations given before the age of one year and one more vaccination given at the age of three and 14 years.
“Most of the UK population will be protected from childhood vaccinations, but in some communities with low vaccination coverage, people may remain at risk,” Saliba said.
Every year, between one and three “vaccine-like” polio viruses are typically found in the British sewer system.
Such detections have always been one-time occurrences and have previously occurred when a person vaccinated abroad with live oral polio vaccine returned or traveled to the UK and briefly “discarded” traces of the vaccine-like poliovirus in their faeces.
However, this is the first time that a group of genetically related specimens has been identified repeatedly over several months.
Scholars say this suggests that there was some community between the closely related people in north and east London.
So far, the virus has only been detected in sewage samples, and no cases of paralysis have been reported, according to the UKHSA.
While polio vaccination is common in the UK, immunization rates vary across the country, with lower coverage communities at greater risk.
Vaccination coverage for children in particular has declined in the country and especially in parts of London in recent years.
The UK National Health Service has said parents should contact their doctor’s clinic to check their child’s vaccines are up to date.
“Most Londoners are fully protected against polio and will not need to take any further action, but the NHS will begin contacting parents of children under 5 in London who have not yet been vaccinated against polio to invite them to receive protection.” Jane Clegg, chief nurse for the NHS in London, said.
“Meanwhile, parents can also check their child’s vaccination status in their Red Book, and people should contact their GP to schedule an appointment if they or their child are not fully vaccinated,” she added.
In 2004, the UK switched from an oral polio vaccine to an inactivated polio vaccine, which is given by injection and prevents infection.
Typically, those who contract polio show no symptoms, although some may develop a flu-like illness up to three weeks later. In more rare cases, the virus can affect the nerves in the spine and base of the brain, which can lead to paralysis. It can sometimes affect the muscles used for breathing, which can be fatal.
Health officials said early detection of the virus would be essential to monitor its spread and prevent more severe cases.
“In populations with low vaccination coverage, live polio vaccine can be passed from one person to another. If this continues, over time (one or two years) this vaccine-derived virus may mutate to become fully virulent again and may start to cause paralysis in people who have not been vaccinated,” said Paul Hunter, professor of medicine. at the University of East Anglia.