Polio has now made an unwelcome reappearance in Africa over five years after the last case of wild polio was detected in the continent.
This new case was in a young child in Lilongwe, Malawi's capital. According to the Global Polio Eradication Initiative, the three-year-old developed paralysis in November 2021 and it has now been confirmed that it was polio.
This virus strain – type 1 wild poliovirus (WPV1) – is genetically linked to the poliovirus circulating in the Sindh Province in Pakistan. The virus, of which there have only been five cases in 2021, is endemic to Pakistan and Afghanistan.
Africa was declared poliovirus-free in August 2020 and this detection does not affect this status as the virus is imported.
“As long as wild polio exists anywhere in the world all countries remain at risk of importation of the virus,” Dr Matshidiso Moeti, World Health Organization (WHO) Regional Director for Africa, said in a statement.
“Following the detection of wild polio in Malawi, we’re taking urgent measures to forestall its potential spread. Thanks to a high level of polio surveillance in the continent and the capacity to quickly detect the virus, we can swiftly launch a rapid response and protect children from the debilitating impact of this disease.”
Polio has affected millions in the last 150 years. Many would get the virus without symptoms, for others it would be flu-like, and for a small minority it would lead to a series of neurological conditions, ranging from muscle weakness to debilitating and occasionally fatal paralysis. Some survivors experience post-polio syndrome, where symptoms present decades later.
Polio is really close to being eradicated. Poliovirus type 2 was eradicated in 1999. The last case of poliovirus type 3 was in Nigeria in November 2012. The only strain still surviving is poliovirus type 1.
“The last case of wild polio virus in Africa was identified in northern Nigeria in 2016 and globally there were only five cases in 2021. Any case of wild polio virus is a significant event and we will mobilize all resources to support the country’s response,” added Dr Modjirom Ndoutabe, Polio Coordinator in the WHO Regional Office for Africa.
There is no cure for polio, but the disease can be prevented with an oral vaccine. This was developed in the 1960s by Albert Sabin, following the first vaccine for the condition developed in the 1950s by Jonas Salk.