The polio virus was recently detected in sewage in London. A serious and contagious infectious disease, it is the subject of careful vigilance in Europe. This detection would be linked to the type of vaccine used in the United Kingdom. Explanation.
Polio, what is it?
The poliomyelitis is a serious and highly contagious infectious disease. The poliovirus is responsible for this, it affects the nervous system. Thus, it can lead, in a few hours, to total paralysis. This virus is transmitted by the faecal-oral route, via contaminated water or food.
The polio mainly affects children under 5 years of age. Its evolution is very variable. Indeed, it can present itself in an asymptomatic form or cause a meningitis or paralysis. Moreover, in 1 out of 20 cases, it causes lasting and very serious sequelae.
Although there is no treatment, preventive measures based on hygiene and vaccination have reduced the incidence of the disease by more than 99%. polio worldwide.
Update on the situation in England
This Wednesday, June 22, the World Health Organization (WHO) confirmed the detection of polioviruses derived from a vaccine in a treatment plant located in London. The latter drains a basin with a population of 4 million people.
Vaccine-derived poliovirus is an attenuated strain originally included in an oral polio vaccine. This virus can evolve through genetic mutations over time until it becomes a virulent form. Excreted in the stools of infected people, it can then be transmitted to people who are not properly vaccinated against polio. Thus, the disease can be transmitted mainly in countries using the oral vaccine.
To date, no cases of paralysis have been detected in England. In addition, the authorities consider that the risk of spread is low, with vaccination coverage estimated at 86.6%.
Polio virus under control in France
What about France? In France, vaccination against polio is not based on the same principle as that practiced in the United Kingdom. Indeed, it is based on the use of an inactivated virus, which does not present the risk of evolution of the oral vaccine.
In addition, vaccination coverage in France is very high, with 99% of the population vaccinated. Indeed, the vaccine against polio was compulsory for children under 12 until 2018. Since then, it has been compulsory for newborns. This excellent vaccination coverage in France is reassuring and needs to be maintained and homogeneous across the entire population.
However, great vigilance vis-à-vis a possible reintroduction of the poliovirus is necessary and implemented by Santé Publique France. Indeed, endemic foci located in Pakistan and Afghanistan persist.
Alexia F., Doctor in Neurosciences