Africa was declared free of wild polio on Tuesday, leaving Pakistan and neighbouring Afghanistan as the only countries thought to still have the highly infectious, water-borne virus .
The announcement by the African Regional Certification Commission for Polio Eradication comes after no cases have been reported for four years. Polio once paralysed some 75,000 children a year across Africa.
Health authorities see the declaration as a rare glint of good news in Africa amid the coronavirus pandemic, an Ebola outbreak in western Congo, the world's worst measles outbreak in Congo and the persistent deadly challenges of malaria, HIV and tuberculosis.
The World Health Organisation says it is just the second time a virus has been eradicated in Africa, after the elimination of smallpox four decades ago.
But sometimes patchy surveillance across the vast continent of 1.3 billion people raises the possibility that scattered cases of wild polio still remain, undetected.
Northern Nigeria
The final push to combat wild polio focused largely on northern Nigeria, where the Boko Haram Islamic extremist group has carried out a deadly insurgency for more than a decade. Health workers at times carried out vaccinations on the margins of the insecurity, putting their lives at risk.
Africa’s last reported case of wild polio was in Nigeria in 2016. The country had been removed from the global list of polio-endemic nations a year earlier, a step towards being declared polio-free, but new cases were then reported in children in the north – a stark example of the difficulties in combating the disease.
This new declaration does not mean Africa is polio-free. Cases remain of the so-called vaccine-derived polio virus, which is a rare mutated form of the weakened but live virus contained in the oral polio vaccine.
That mutated virus can spark crippling polio outbreaks, and 16 African countries are currently experiencing one: Angola, Benin, Burkina Faso, Cameroon, Central African Republic, Chad, Ivory Coast, Congo, Ethiopia, Guinea, Ghana, Mali, Niger, Nigeria, Togo and Zambia.
Coronavirus focus
Health authorities have warned that the coronavirus pandemic has disrupted vaccination work in many countries across Africa, leaving more children vulnerable to infection.
In April, the WHO and its partners reluctantly recommended a temporary halt to mass polio immunisation campaigns, recognising the move could lead to a resurgence of the disease. In May, they reported that 46 campaigns to vaccinate children against polio had been suspended in 38 countries, mostly in Africa, as a result of the coronavirus pandemic.
Eradicating polio requires more than 90 per cent of children being immunised, typically in mass campaigns involving millions of health workers that would break the social distancing guidelines needed to stop the spread of Covid-19.
Health officials had initially aimed to wipe out polio by 2000, a deadline repeatedly pushed back and missed. Even now in northeastern Nigeria, thousands of children remain out of reach of health workers carrying out vaccinations. – Reuters