In 1988 the World Health Assembly passed a resolution calling for the eradication of polio by 2000. There were 350 000 cases in 1988, and by 2000 the number had been reduced by 99%—to around 600. Since then the number has stuck at around 600, and there is anxiety that the last 1% of cases will not be eradicated. Worse, if that 1% cannot be eradicated then the number is likely to climb again to tens or hundreds of thousands of cases.

Eradicating polio is an intellectual, scientific, public health, financial, and political problem, said Sir Liam Donaldson, former chief medical officer in England and now chair of the International Monitoring Board for the Global Polio Eradication Programme, in the annual lecture of Imperial College’s Institute for Global Health Innovation. The monitoring board was established after a review of the programme, and it’s job is to eradicate the 1%. It is, said Donaldson, more of a people than a science problem.

The world of polio can be divided into four groups: those countries where polio is safely eradicated; those where it persists; those where it has re-established itself; and those where there outbreaks still occur linked to cases from countries where polio continues. The last group is large and includes China.

Afghanistan, Pakistan, and Nigeria are the countries where polio has never been eradicated. India was one of those countries, but after a massive effort where 2.5 million health workers vaccinated 174 million children in three days, polio has been eradicated in India.

War is the main barrier to eradication in Afghanistan. Some 270 000 children cannot be reached. Security issues are also part of the problem in Pakistan, but governance is the main issue, said Donaldson. The ministry of health has been abolished, organisation is poor, and corruption undermines the programme. A successful programme, emphasised Donaldson, depends on highly detailed planning and dedicated health workers who are willing to track children through dense slums and across deserts and spend 30 minutes persuading a mother that her child will benefit from being vaccinated. He showed us a film of a worker in Pakistan who described how she was working so intensely on vaccinating children that at night “I dream that I’m vaccinating children.”  We need commitment from political leaders, said Donaldson, but without dedicated and well organised health workers eradication won’t be achieved.

Cases in Nigeria are concentrated in the Muslim north, and parents often refuse  vaccination for religious and superstitious reasons. People are told that the vaccines come from the CIA and are actually contraceptives designed to reduce the number of Muslims. Some politicians actively campaign against vaccination in elections, and the Boko Haram, the “Nigerian Taliban,” are becoming increasingly active in northern Nigeria. Polio in Nigeria is particularly important because it is the source of outbreaks in other African countries.

Polio has re-established itself in Angola, the Congo, and Chad because of war and lawlessness. Geography presents a barrier to eradication in many countries but particularly in Chad, where small groups live scattered in islands in Lake Chad that may take hours to reach.

Despite the problems of geography, war, insurgency, politics, communication, finance, and people management, there are optimistic signs, said Donaldson. Polio has been eradicated in India, and there does seem to be a dip in the number of cases in early 2012. The aim now is to eradicate polio this year, and it could, said Donaldson, happen very quickly. This is, he concluded, a “unique moment in public health”: with one last heave the disease could be eradicated, but if it isn’t financial backing will disappear, health workers will not be paid, systems will break down, and cases of polio will rise back into the tens or hundreds of thousands.

Postscript: Donaldson began his lecture by describing how when he was 5 in 1954 a playmate had developed a paralytic polio. A few days later he had developed a sore throat, and his parents were intensely worried about him developing paralytic polio. I was born in 1952 and remember talk of polio, but for me it was never a dread disease. I’ve realised this year how lucky I was by reading Nemesis by Philip Roth, who is perhaps the greatest living writer. He evokes powerfully the fear that swept through  a playground in Newark one summer during the Second World War as child after child developed polio, some dying within hours and others spending weeks in iron lungs. If you want to feel the fear and suffering that polio can create then read the book; it’s short and can be read in a few hours.

Competing interest: RS is an unpaid adjunct professor in the Institute for Global Health Innovation.

RS was the editor of the BMJ until 2004 and is director of the United Health Group’s chronic disease initiative.