LONDON/GENEVA--After two years in which the disease appeared beaten in Africa, polio eradication hopes hang in the balance with two cases of paralysis in Nigeria suggesting the virus has fought back, UN experts said on Friday.
Many more cases of polio paralysis could come to light as investigators go into areas of northeastern Nigeria where the country's first cases in the two years were confirmed on Thursday. "There could very well be more cases," Michel Zaffran, head of polio at the World Health Organization, told reporters in a series of briefings.
He said health authorities would be carrying out detailed surveillance in the state of Borno and surrounding areas to see whether and how many other children might have been affected. "If this virus has been circulating for several years, there's a risk many more children have been paralysed. We need carry out intensive and active surveillance to identify them."
The polio virus, which invades the nervous system and can cause irreversible paralysis within hours, spreads rapidly among children, especially in unsanitary conditions in war-torn regions, refugee camps and areas where healthcare is limited. Experts estimate that for every case of polio that paralyses its victim, 200 silent infections go undetected.
The WHO said it is planning a large, rapid response to the disease's re-emergence in Nigeria, beginning next week with emergency vaccination campaigns in four local government areas near the two confirmed cases.
The Islamic extremist group Boko Haram is active in Borno and instability in the northeastern state has hampered efforts to get vaccines to children at risk. But Zaffran said health authorities would work with local religious and community leaders to try to ensure better access.
Beyond that, emergency national immunization rounds will also be carried out in Nigeria and neighboring countries of Chad, Cameroon, Niger and the Central African Republic. "There is a very active response being planned to ensure that we interrupt this outbreak and do not allow it to spread to neighboring countries," Zaffran said.
