For the first time in more than five years, a case of polio has emerged in Africa.

As the World Health Organization (WHO) announced, a so-called wild type 1 polio virus was detected in a small child in the Malawian capital Lilongwe.

Peter Philipp Schmitt

Editor in the department "Germany and the World".

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Africa was officially declared polio-free by the WHO in August 2020 after all wild forms were eradicated and no longer spread across the continent.

Initial laboratory tests showed that the virus that has now been detected is genetically linked to a pathogen that circulates in the province of Sindh in Pakistan.

Only in Pakistan and Afghanistan is polio still endemic.

"All countries are at risk of polio being re-imported"

"As long as there is polio anywhere in the world, all countries are at risk of polio being re-imported," said WHO Africa Region Director Matshidiso Moeti.

Everything must now be done to prevent poliomyelitis from spreading further in Malawi.

The last case of type 1 wild poliovirus was reported in Nigeria in 2016.

Last year, the WHO reported a total of just five cases around the world.

In this respect, according to the WHO, each case is “a significant event”.

Poliomyelitis, or polio for short, is a highly contagious infectious disease.

Infection of the central nervous system can lead to paralysis.

However, this only happens in about one percent of all infections.

In addition to wild virus infections, so-called vaccine virus infections also occur.

The polio vaccine taken orally is a weakened live vaccine. After an oral vaccination, the viruses multiply in the gastrointestinal tract for several weeks and can also be excreted and transmitted in this way.

However, these pathogens only become dangerous if they encounter a population with too low a polio vaccination rate, because vaccination viruses that have been circulating for a long time can change genetically and then also cause symptomatic diseases.

In recent decades, polio vaccination has led to the fact that polio has almost been eradicated.

At the end of the 1980s, more than 350,000 endemic cases were detected in almost 130 countries.

Since then, large-scale vaccination campaigns have completely eliminated two of the three wild virus types, which differ in some of their proteins.

The WHO declared type 2 eradicated in September 2015 after the last known case occurred in India in 1999. Type 3 was last seen in Nigeria in November 2012 and has been officially eradicated since October 2019.

Only type 1 still occurs, for the first time outside of Afghanistan and Pakistan.

The WHO is concerned that many children in poorer regions were less vaccinated, especially at the beginning of the corona pandemic.

Recently, however, the vaccination campaigns have been better again, and the long-established polio task forces in many countries are now also immunizing against Covid-19.