"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."