The Guardian view on African success: a step closer to conquering polio | Editorial

We are tantalisingly close to eradicating the disease. Things may slip backwards because of science, thugs and exponents of ignorance

Polio arrives, if it announces itself at all, as a high temperature. Or a sore throat. Maybe a headache, or an upset stomach. It can go within a week or so, and be mistaken for flu. It is transmitted by poor hygiene, largely affects children under five, and many don't realise they've had it. In 5-10% of cases, however, the virus affects the nerves, paralysing the legs in particular; sometimes it reaches the lungs. For most, this is temporary. For others - 30 years ago, this was 350,000 children a year - paralysis is permanent, and if it is of the lungs, they die. No one who has seen the effects of polio forgets.

In the early 20th century epidemics were frequent; in the United States transmission was blamed on everything from cats to blueberries to Italian immigrants. By the early 1950s, the US public ranked it second as its worst fear after nuclear war. When, in 1955, a vaccine was developed, the British held street parties. The numbers of cases dropped immediately. In 1960, Czechoslovakia was first to declare eradication. The last recorded case of naturally occurring polio in the UK was in 1984. Polio was declared gone in the Americas in 1994; in the western Pacific region (including China) in 2000; in Europe in 2002; India and south-east Asia in 2014. Last week, Africa joined their number. Only Pakistan and Afghanistan remain.