Though only 650 cases were recorded last year, the World Health Organization declared the disease an emergency, but its importance goes beyond public health.
Few people probably associate the phrase "global health emergency" with polio, a disease that has been around for 5000 years and is on a decades-long decline so steep that there are less than a thousand recorded cases left on Earth, and it no longer even seems real to many in the developed world. "Global health emergency" might sound applicable to HIV/AIDS, malaria, or cancer, but polio?
And yet, that is exactly what happened late last Friday afternoon in Geneva, when the World Health Assembly, the governing body of the World Health Organization, declared polio a public health emergency, calling for the 194 member states to fully fund the Global Polio Eradication Initiative, and fill the currently $945 million gap in its budget for 2012-13. But this is about much more than just filling a budget shortfall: polio's threat is still very real, and the mission to finally stamp it out forever is a crucial one for reasons even bigger than the disease itself.
Since the world decided to come together to eradicate polio in 1988, the disease has been almost entirely eliminated. It killed or paralysed more than 350,000 children each year in the 1980s, but there were just 650 recorded cases in 2011. In January, India celebrated its first polio-free year in history, leaving the disease endemic in just three countries: Nigeria, Pakistan and Afghanistan. The latest figures from the World Health Organization show only 60 cases so far in 2012.
But polio is a different type of emergency than the ones we usually hear about in the news. Its biggest danger isn't the current number of cases, but the implications for failure: not only because a failure to eradicate could allow for a resurgence that could kill or disable thousands of children each year, but because of what it holds for the effectiveness of our global health systems itself.
Part of the risk has to do with money. Over the past quarter century, $9.5 billion has already been spent on polio eradication, driven by international organizations -- primarily the WHO and UNICEF -- as well as private donors such as the Gates Foundation and Rotary. The WHO's strategic advisory group of experts on immunization have said that failure to eradicate polio would be "the most expensive public health failure in history." A failure to make all that money achieve its intended goal could make it tougher to solicit donations from countries and individuals for future eradication campaigns.
The other element is symbolic. In a sense, polio will be a marker of either what the world can or cannot achieve in global health. "If we finish polio eradication, what it will prove is that with a relatively modest investment in the grand scheme of things, you can achieve real health outcomes," says Bruce Aylward, the Canadian epidemiologist who heads the WHO's eradication efforts.
Wiping out a disease is a difficult business. It is a feat we've achieved only once before, with smallpox in 1979. It's not that we lack the technology: the first polio vaccine was created by Jonas Salk in 1954, following the horrific 1952 epidemic in the United States, and the oral vaccine commonly used in the developing world was created by Albert Sabin in 1963. The real challenge is ensuring that the vaccine reaches every single child, especially those children likely to be missed by routine vaccination programs: those in the poorest, most remote corners of the globe.
For a disease like polio, the challenge is steeper still. Where almost everyone infected with smallpox develops a distinctive red rash, allowing sufferers to be identified and quarantined, polio has no visible effects on 99 percent of people who carry the virus. Its relative invisibility allows it to travel undetected, seeping into vulnerable pockets and popping up seemingly at random.
"What we've seen in the past 10 years is, as soon as you relax your control measures, polio comes back in far greater numbers," Michael Toole, Deputy Director of the Burnet Institute in Melbourne and a member of the eradication initiative's independent monitoring board, told me. He points to outbreaks in China in 2011 as well as Tajikistan and the Democratic Republic of the Congo in 2010 -- all countries previously declared polio-free. In 2005, there was a polio outbreak in an Amish community in Minnesota, infecting five children but paralyzing none.
Like any virus, polio has to come from somewhere. The WHO uses genetic sequencing to trace the path of each case across communities, cities, and even national borders. But the fact that so few of the people who carry polio display symptoms can make it almost impossible to contain.
The resurgence of an old disease can be especially dangerous, as the world has learned before. In the 1950s and 1960s, the use of the insecticide DDT led to a reduction in the population of mosquitoes, which in turn decreased the number of deaths due to malaria. But the effects were temporary, and when the disease resurged, people had lost some of their natural immunity, and deaths spiked.
We've had similar warning signs with polio as well: the 2010 outbreak in the Congo, for example, had a 50 percent morbidity rate, WHO spokesperson Sona Bari told me, more than twice what is usually seen in unimmunized populations. "If we fail, we are not going to continue to have 50 kids paralysed each year, we're going to have hundreds of thousands," Aylward said.
But though polio is difficult to contain, it is looking increasingly possible to eradicate, largely due to the success in India last year. " I have a tremendous heart for India," says Sir Gustav Nossal, a renowned Australian immunologist who consults to the Gates Foundation. "If you go to Uttar Pradesh and Bihar, where the last pockets of the virus were in India, they are devastatingly poor. They have areas that are extremely inaccessible, that are flooded just about every single year and can't be reached for four months during the monsoon season. And yet, the Indians did it. They did it because of leadership and passionate commitment. That's what we now need from Nigeria, Pakistan, and Afghanistan."
Polio is sometimes framed as a moral issue: a question of whether all children have the right to safety from a deadly and debilitating disease, a safety that those of us in the wealthier parts of the world take for granted. And, to some degree, it is. As Rotary International's Carol Pandak puts it, "The specter of 200,000 children each year being paralysed by polio in the future seems unthinkable when you when there are resources available."
But the Western world has its own reasons to care, as well: a strong, proven, credible global health system, able to contain and eradicate diseases. Bill Gates, in his 2011 annual letter, called this "the rich world's enlightened self-interest."
In public health circles, it is common to hear about the "symbolic" importance of polio: how halting it would be a victory for public health, and how not taking advantage of the opportunity when the number of cases is so low would be a failure so devastating that it would make it difficult to pursue more such worldwide projects. But that symbolism also has very practical applications.
Aylward recalled a speech by Indian Prime Minister Manmohan Singh At the polio summit in Delhi in February, a celebration of country's first polio-free year in history. Singh spoke about how success on polio had given his government the confidence to tackle other health issues, such as measles and malnutrition, and had bolstered his plans to create new public health cadres to work for the prevention and control of disease. "The success of our efforts show that teamwork pays."
Update, June 1: Aylward, who leads the WHO polio effort, writes to explain a distinction in how the word "emergency" applies here. "This is not a PHEIC [public health emergency of international concern] but a 'programmatic emergency for global public health,' where the disease and tools to prevent it are well understood," he said in an email. "The emergency in the latter context is to apply the knowledge and tools, using an emergency approach to eliminate future epidemic and endemic polio."