Heartbreak hit Nigeria on Thursday (Aug. 11) as two new cases of polio set back global efforts that had come within striking distance of eradicating the disease for good.
The World Health Organization (WHO) announced that two children, one 15 months old and another two years old, in Nigeria’s northeastern state of Borno have been paralyzed by polio, breaking what would have been two straight years of a polio-free African continent this month.
DNA analysis of the viruses revealed that they were closely related to a Type 1 strain of poliovirus that is native to Nigeria but hadn’t been seen in Borno since 2011.
Experts blamed gaps in polio surveillance but also instability in the region—potentially due to the presence of the terrorist group Boko Haram—which has restricted the movement of vaccination campaigns and displaced thousands of people. As many as half a million children may not have received the required dose of vaccination for the last two years, experts told told Stat.
Polio is one of the world’s most ancient diseases. The virus that causes the illness is highly infectious, often spread through food or water contaminated with feces. Poliovirus invades the nervous system, causing muscle weakness and, in some rare occasions, paralysis. Most often paralysis occurs in the legs but sometimes can affect the muscles required for breathing, which can lead to death for 5-10% of those suffering paralysis.
And polio is as stubborn as it is devastating. Because only 1 in 200 people suffer paralysis—more common symptoms are fever, fatigue, stiff necks, and limb pain—the virus can easily go undetected.
There is no cure for polio. But an oral polio vaccine, if administered on the suggested schedule (four doses overall, one each at at two months old, four months old, 6-18 months old, and 4-6 years old), protects a child for life.
Polio is one of the few diseases with a character that means it could be completely eradicated (only one disease—smallpox—has ever been completely eradicated). Unlike zika or HIV, for example, poliovirus has no intermediate animal host—like mosquitoes, bats or rats—and can only survive for two months outside of the body. In other words, if we can immunize enough people, poliovirus will be forced out into the open environment, where it will eventually just die out.
And we had come really close. According to the Global Polio Eradication Initiative, only 21 polio cases had been reported so far in 2016, down from 34 cases at the same point in time last year. Two of the three strains of wild polio have been eradicated, leaving only Type 1. And, until this week, polio existed in just two remaining countries: Afghanistan and Pakistan. Campaigners like Bill Gates believed 2017 might have seen the last case of wild polio infection anywhere in the world. And, as recently as in 2012, Nigeria accounted for over half of the world’s polio cases.
According to the Global Polio Eradication Initiative, local conflict played a major role in the setback, The Initiative works with local governments, health ministries and communities on vaccine rollouts and conducts follow-up surveillance themselves. Even in war-torn areas, such as in Afghanistan, vaccinators can often negotiate ceasefires to allow them to vaccinate children. This wasn’t possible in Borno, where locals wanted to get the vaccinations, but Boko Haram wouldn’t let it happen. Michel Zaffran, director of polio eradication at the World Health Organization, told a press conference that it’s the only area they’ve come across such resistance.
It’s unknown how many cases there are or how widespread the Borno outbreak is. For now the priority is to rapidly immunize as many of the approximately 100,000 children in the affected area as possible, Zaffran told Quartz. The Initiative is launching an immediate emergency vaccination program, starting with Borno, then expanding nationally and to neighboring countries around the Lake Chad basin: Cameroon, the Central African Republic, Chad, and Niger.