Eradicating Polio: So Close, Yet So Far

Excellent update in today's NYT on the continuing drive to wipe out polio. This article discusses why it's so difficult to finish the job - some clips below:

Nearly 18 years ago, in what they described as a "gift from the 20th century to the 21st," public health officials and volunteers around the world committed themselves to eliminating polio from the planet by the year 2000.

Since then, some two billion children have been vaccinated, cutting incidence of the disease more than 99 percent and saving some five million from paralysis or death, the World Health Organization estimates.

But six years past the deadline, even optimists warn that total eradication is far from assured. The drive against polio threatens to become a costly display of all that can conspire against even the most ambitious efforts to eliminate a disease: cultural suspicions, logistical nightmares, competition for resources from many other afflictions, and simple exhaustion. So monumental is the challenge, in fact, that only one disease has ever been eradicated — smallpox. As the polio campaign has shown, even the miracle of discovering a vaccine is not enough.

Not least among the obstacles is that many poor countries that eliminated polio have let their vaccination efforts slide, making the immunity covering much of the world extremely fragile, polio experts warn. They compare it to a vast, tinder-dry forest: if even one tree is still burning, a single cinder can drift downwind and start a fire virtually anywhere.

Here in northern India the embers are still glowing. And northern Nigeria, another densely populated, desperately poor region, is aflame.

In a calamitous setback in mid-2003, Nigeria's northern states halted the vaccination campaign for a year after rumors swept the region that the vaccine contained the AIDS virus or was part of a Western plot to sterilize Muslim girls. Within a couple of years, 18 once polio-free countries have had outbreaks traceable to Nigeria. Though most have since been tamed, Indonesia and Nigeria itself remain major worries. In 2001, there were fewer than 500 confirmed cases of polio paralysis in the world. Last year, the number jumped to more than 1,900 — and each paralyzed child means another 200 "silent carriers" spreading the disease.

This year in addition to India and Nigeria, cases have been reported in Somalia, Niger, Afghanistan, Bangladesh and Indonesia.

Yet no eradication effort against any disease has been as well financed or as comprehensive as the polio drive, which has cost US$4 billion so far. In the balance is not just whether polio will be extinguished, many public health officials say, but whether a world that could not quite conquer polio will have the stomach to try to wipe out other diseases, like measles. The closer a disease is to eradication, they say, the harder-won the gains. Interest lags as the number of cases falls. Fatigue sets in among volunteers, donors and average people. Yet even one unvaccinated child can allow a new pocket of the disease to bloom.

Here and elsewhere, eradicating polio means finding ways to get polio drops into the mouths of every child under 5 — over and over. Because it can take many doses to effectively immunize a child in parts of the world where the disease circulates intensely, eradication requires repeated sweeps. Campaigns are planned to the smallest detail. Each lane is mapped. Supervisors shadow vaccination teams. Follow-up specialists pursue resistant families. "Here, polio eradication has been going on for 10 years, and that's too long," said David C. Bassett, 63, an old smallpox hand sent to India by the World Health Organization to help with polio. "The public's sick of it. The workers are sick of it. The government's sick of it. We're close now. We need to mobilize resources. The donors aren't going to keep putting up money for this forever."