Polio is re-emerging worldwide

Polio is re-emerging worldwide

Recently, researchers have detected the poliovirus in the sewage system in east London on a number of occasions this year. Its original source is likely to be someone recently inoculated with an oral version of the polio vaccine. But according to WHO report cases due to wild poliovirus have decreased by over 99% since 1988, from an estimated 350 000 cases then, to 6 reported cases in 2021.

The discovery of poliovirus in New York state, London and Jerusalem this year has taken many by surprise but public-health researchers fighting to eradicate the disease say it was only a matter of time.

The virus found in these regions is derived from an oral polio vaccine used in some countries. So far, only two cases of polio-related paralysis have been reported, in Jerusalem in February and New York in June1; the New York infection was the first such US case in nearly a decade. But wastewater samples in all three areas suggest that the virus is circulating more widely.

What are Polio symptoms ?

The majority of people with the infection have no symptoms but some feel as if they have the flu, with:

> a high temperature
> sore throat
> headache
> stomach pain
> aching muscles
> feeling sick

Why are these outbreaks happening?

The most obvious explanation for the reemergence of polio in some countries are that only about 50 percent of residents are vaccinated against polio. Most unvaccinated people who contract the virus don’t get sick at all or have mild illness, and about 25 percent will get mild flu-like symptoms. There’s two main forms of polio virus: There’s the wild-type virus, which is seen in endemic countries, then there’s what’s known as vaccine-derived polio — the type detected in New York and London’s wastewater.

Further readings:

What polio’s UK presence means for global health

Spate of polio outbreaks worldwide puts scientists on alert

Poliovirus in London sewage sparks alarm