Polio: The Once Defeated Crippling Virus Now Returns

Epidemics in the 19th and 20th centuries left millions disabled and thousands dead, until global post-WWII vaccination campaigns all but eradicated the virus. However, recent outbreaks have caused concern.

The deadly disease poliovirus is once again rearing its head after being previously eradicated in most of the world, with potential outbreaks detected in India, Israel and now the British capital London.

Poliovirus primarily infects the digestive tract, and, like most enteric diseases, is spread by people practising poor hygiene and contaminating food with faecal matter.

In about one in 200 cases the virus will spread to the central nervous system, attacking neurons in the spinal cord and even the brain stem. This can cause flaccid muscle weakness or paralysis of the limbs and even damage the nerves that control the face, eye focus and breathing if it reaches the lower brain.

Up to five per cent of children and 30 per cent of adults with spinal polio will die, but most sufferers have either mild symptoms or none at all.

Polio survivors can also often suffer deformities caused by flaccid muscle paralysis, including shortened or bowed arms and legs and equinus foot - where the toes curl downward and the Achilles' tendon shortens until the patient can no longer walk.

The first successful vaccine against polio was developed in 1950 by Polish virologist Hilary Koprowski, based on an attenuated - weakened and less virile - live strain of the virus. Other vaccines followed, including the orally-administered liquid form familiar to those who grew up in the late 20th century. Nowadays, an injected vaccine is preferred in most countries.

Worldwide vaccination campaigns all but wiped out the terrible virus, to the point where the only 'wild' cases identified between 2018 and 2022 were in war-torn Afghanistan and neighbouring Pakistan.

Famous polio survivors include actors Donald Sutherland and Alan Alda, as well as British singer Ina Dury. Dury campaigned with UNICEF for the eradication of polio, but also made light of his resulting disabilities in the song 'Spasticus Autisticus'.