Public health officials have declared a national incident after routine monitoring of wastewater in north and east London found evidence of polio virus transmission in the community for the first time.
The UK Health Security Agency (UKHSA) said waste from its Becton wastewater treatment business in Newham tested positive for vaccine-derived poliovirus in February, and that other positive samples have since been detected.
No cases of the disease or associated paralysis have been reported, and the risk to the general public is considered low, but public health officials have urged people to ensure they and their families are up to date with polio vaccines to reduce the risk of harm. .
Dr Vanessa Saliba, a consultant epidemiologist at UKHSA, said: “Vaccine-derived poliovirus has the potential to spread, particularly in communities where vaccine uptake is lower.” “In rare cases, it can cause paralysis in people who are not fully vaccinated, so if you or your child is not up to date with the latest polio vaccines, it is important to call your GP to catch up or if an item from your Red Book checks .”
She added: “Most of the UK population will be protected from childhood vaccination, but in some communities with low vaccine coverage, individuals may still be at risk.”
Tests on UK wastewater usually catch a few unrelated polioviruses each year. These come from people who received the oral polio vaccine in another country and then traveled to the UK. People given the oral vaccine can shed the live attenuated virus used in the vaccine in their stools for several weeks.
The London samples discovered since February raised alarm because they were linked together and contained mutations that suggested the virus evolves as it spreads from person to person.
The outbreak is believed to have been caused by a person who returned to the UK after taking and spreading the oral polio vaccine locally. It is unclear how widespread the virus is, but it may be limited to a single family or an extended family.
The polio virus can be spread through poor hand hygiene, contaminated food and water, or more often through coughing and sneezing. A common way of transmission is by getting people infected with contaminated hands after using the toilet and then transmitting the virus by touching food that others have consumed.
While the UK generally has good uptake of the polio vaccine, with 95% of five-year-olds getting the vaccine, coverage is lagging in London, where only 91.2% of children in that age group have been vaccinated. In response to the discovery of the virus, the NHS will contact parents of children who have not kept up with their polio vaccinations.
Most people infected with polio have no symptoms, but some develop a flu-like illness after three weeks. In about 1 in 100 infections and 1 in 1,000 infections, the virus attacks the nerves in the spine and the base of the brain, which can lead to paralysis, most commonly in the legs. In rare cases, the virus attacks the muscles used for breathing, which can lead to death.
The United Kingdom switched from using oral polio vaccine (OPV) to inactivated polio vaccine (IPV), which is given by injection, in 2004. Vaccines in routine NHS pediatric vaccinations are given at eight, 12 and 16 weeks as part of a 6-week period . Vaccine at 1. Boosters are offered at ages three and fourteen.
UKHSA is now analyzing samples of sewage from local areas that feed the Beckton plant to narrow the spread of the virus. If these tests identify the epicenter of the outbreak, public health teams may offer polio vaccination to those at risk.
Professor Nicholas Grassley, Head of the Epidemiological Vaccine Research Group at Imperial College London, said: “Polio is a disease that persists in some of the world’s poorest regions, and the UK often detects importation of the virus during routine wastewater testing.
In this case, there is concern that the virus may spread locally in London and could spread more widely. Fortunately, no one has yet shown symptoms of the disease, which affects only 1 in 200 of those infected, but it is important that children are fully aware of the polio vaccines. Until polio is eradicated globally, we will continue to face the threat of infectious disease.”