London Sewer Poliovirus-What You Need to Know

As I thought Monkeypox The UK Health and Security Agency (UKHSA) has declared a national incident of repeated poliovirus detections in the sewers of northern and eastern London, which will be a threat of new viruses in 2022. Repeated positive measurements of polio suggest an ongoing infection and possible infection in the area. This is unexpected because the UK has been declared polio-free since 2003.

Here’s what you need to know:

Polio is a devastating disease that has historically caused paralysis and death around the world. It is caused by poliovirus, a small RNA virus that can damage cells of the nervous system.

Not found in animals, it can be eradicated like smallpox. And thanks to effective vaccination campaigns, we are approaching this goal every year.

There are three types of poliovirus, and infection or immunity from one type does not protect another. Type 1 poliovirus continues to cause outbreaks, but infections with types 2 and 3 have been successfully interrupted by vaccination.

A national incident was declared after the discovery of polio in London’s sewers. How did you get there, so do you have to worry?

Our science and technology editor, @aTomClarke Description ? https: //t.co/GWmOo5pABr pic.twitter.com/ZOzTd8h4Gh

–Sky News (@SkyNews) June 24, 2022

Poliovirus is transmitted by respiratory droplets, but it can also be transmitted from food and water that come in contact with the feces of people who carry the virus.

It can survive at room temperature for days. The last remaining outbreak is associated with poorly sanitized areas that are difficult to reach with vaccines. Afghanistan and Pakistan are the only countries where wild polio is still endemic and are subject to eradication programs to prevent the virus from spreading to other countries.

The important role of vaccines

Vaccines are essential for the eradication of polio. In 2021, less than 700 cases were reported worldwide.

Injected polio vaccine is used in the United Kingdom. It contains an inactivated virus (IPV) and is safe and effective in protecting immunized people from paralysis, but it is less effective in inducing local immunity in the intestine, so vaccinated people It can infect and release infectious viruses. Indicates the symptom itself.

Where was it detected?

Between February and May, several closely related polioviruses were found in sewage samples.

Authorities believe that there is some spread among individuals in northeast London and they are shedding type 2 poliovirus in their faeces. pic.twitter.com/z0JxTvZcRT

–Sky News (@SkyNews) June 22, 2022

IPVs provide excellent protection for individuals, but they are not sufficient to control epidemics in poor hygiene. An oral polio vaccine (OPV) containing a living but weakened virus is ideal for this purpose. OPVs are drop-managed and do not require trained staff or sterile equipment to manage, allowing you to reach a larger community.

This vaccine can induce strong intestinal immunity and prevent the release of wild poliovirus. Because it contains live viruses, it can also spread to close contact with immunized people and protect them. It is also cheaper than IPV.

The disadvantage of using OPV is that the weakened virus can mutate and, in rare cases, return to the paralyzing mutant.

OPV is cleared by the immune system within a few days, but it may not be the case for people who have a weak immune system and may carry the virus longer, increasing the likelihood of mutations. In under-immunized countries, this can lead to circulating vaccine-derived poliovirus (VDPV). In fact, the virus detected in London’s sewers was VDPV type 2, a vaccine-derived species. There are no wild polioviruses in the UK yet.

Vaccine-derived polio can cause asymptomatic infections in people vaccinated with IPV and is excreted in the faeces due to the lack of local intestinal protection by IPV. Therefore, it can be detected in sewage.

The detection method is sensitive, but a single positive reading does not raise an alarm. Type 1 VDPV was recently detected in the sewers of Kolkata. It is believed that this is due to a case in which a vaccinated person with weakened immunity was imported because the vaccine strain could not be eliminated from the body.

There are no reports of polio-related paralysis in the United Kingdom.

In order to prevent illness, it is necessary to provide up-to-date information on vaccination to families, especially children who may have skipped the vaccination course due to a COVID pandemic. IPV is safe, free and effective in preventing polio. Unlike monkeypox vaccines, which are available to undersupplied and high-risk groups, IPV is readily available to everyone in the UK through the GP.