Coping with river blindness

Twenty-five years ago, the WHO launched a project to eradicate the disease, onchocerciasis, which was a major public health problem in the region.

In some parts of West Africa, 60% of the population had been infected, and 10% were blind.

The economic impact of the disease was devastating. Millions fled their villages to escape, leaving some of the region's most fertile areas uncultivated.

The WHO, together with 11 West African countries, launched a campaign to fight against the black fly that transmits the illness.

The insect, which breeds in fast flowing rivers, bites its victims, leaving behind parasitic worms which spread through the body, and eventually cause blindness.

Helicopters were used to spray an insecticide which was chosen to cause minimal ecological damage. A drug, invermectin, was also developed to combat the disease.

Millions saved

There are concerns that the fly has not completely died out

The WHO says millions of people have been saved from potential blindness, and large tracts of riverside land can be lived in and cultivated again.

Villagers have been gradually returning to areas deserted decades ago for fear of the disease.

But the organisation has warned against complacency until the black fly is completely eradicated