The virus, which has been almost suppressed worldwide, has been detected in big cities. Here we collected questions about urban polio cases. They are answered by a leading expert Carita Savolainen-Kopra From the Institute of Health and Welfare.
1. What are the New York, London and Jerusalem cases about?
Cases are individual.
– It is about the modified polio type 2 virus from the live polio vaccine. They have caused paralysis symptoms to one person in New York, and several findings have been found in samples taken from the waste water, says Savolainen-Kopra.
– In London and Jerusalem, cases with symptoms of paralysis have not been found, but sewage has been found. there are several. Local health authorities in the regions have recommended booster vaccines to improve polio vaccination coverage and stop the virus from circulating.
Polio was declared eradicated from Europe in 2002.
2. How does the virus detected in the West differ from infections in, for example, Afghanistan and Pakistan?
In the world, polio is endemic, i.e. a virus widely circulating in the population, only in Pakistan and Afghanistan.
– In Pakistan and Afghanistan, there is still a type 1 virus left, which is called a wild virus. In the cases of New York, London and Israel, the virus has originated from the polio vaccine, from which it has then mutated back into a wild-type-like virus. Now it can then cause a disease with paralytic symptoms.
3. How were the cases in New York, London and Israel discovered?
Viruses can be traced, for example, on the basis of wastewater findings.
– Urban cases were first detected in sewage, but in New York, paralysis symptoms were found in an unvaccinated person.
4. How serious is it?
The cases are a reminder that the polio virus must also be taken seriously. If the vaccination programs are weakened, polio will make a comeback, because natural protection does not come from contracting the disease.
– The fact that findings about wastewater are made repeatedly for several months indicates that there is a circulation under the radar and it is now occurring in the population.
– Polio typically does not cause any kind of symptoms to everyone infected, or the symptoms can be mild, similar to a respiratory infection. Paralysis-like symptoms are caused by only a few people and there haven’t been very many of them so far.
5. How can infections be prevented?
Vaccination coverage must be maintained.
– The spread can be prevented with vaccines. The background to the presence of the virus is that there are groups of unvaccinated people in the population. From these places, the virus can start to circulate, whether it is a wild virus or a vaccine-based virus that has entered the community.
– It seems that the maintenance of vaccine coverage has at some point weakened.
– In practice, the virus is combated by reminding young children of the need for vaccines, and by making it more effective to inform adults that the full series of vaccinations should be taken.
6. Defeating polio has been one of the world’s health care success stories, why has it been so difficult to tame it?
Polio has been eradicated by vaccines almost everywhere in the world with the help of vaccines developed in the 1950s.
– WHO’s polio eradication program has been a worldwide success and proof that when you invest in health for the whole of humanity, you get results. Wild poliovirus 2 has been completely eradicated from the world.
– Eliminating polio is difficult because it is easily contagious. When it doesn’t cause symptoms for everyone, the virus can spread secretly and not be noticed.
7. Can the virus spread in Finland?
There is no vaccine containing a live virus in use in Finland.
– In Finland, people were vaccinated with a live vaccine in 1985, when the vaccine was distributed to everyone in a piece of sugar. Nowadays, an inactivated vaccine is used and polio monitoring through wastewater is also effective, says THL’s Carita Savolainen-Kopra.
The last case of polio in Finland was observed in 1985. THL monitors the possible circulation of polioviruses in the population by looking for viruses in waste water samples. Wastewater samples are collected regularly from five different cities. Approximately one third of Finland’s population lives in the area of the monitored sewerage networks.
Read more:
Polio is spreading in New York – Finnish expert: The disease has been absent for so long that its seriousness is forgotten