Deep in the slums of Pakistan's biggest city is a 15-months-old boy with a problem that could, perhaps should, have been conquered long before he was born.

Mustafa crawls happily across the dirt floor of his home in Karachi, but when his mother tries to stand him up his difficulties become obvious.

His leg is visibly weak and his foot twisted and hanging uselessly at an odd angle.

While most of the world has consigned polio to history, as ITV News Diplomatic Correspondent John Ray reports, Mustafa's world will be confined by its crippling effects.

(Footage credit: Evan Williams Productions)

Director/Shooter: Haider Ali

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