River blindness.

The fifth in a 10-part series investigating diseases from around the globe. Each programme features a single disease and looks at attempts to develop treatments that are effective and affordable to the world's poor who make up the majority of the victims. This part features River Blindness, a parasitic disease carried by the worms of black flies - 37,000,000 Africans are infected. The disease can be eliminated by the medication, Mectizan, and a programme is underway to persuade African villagers to take the medicine once a year, every year. The organisation of this programme is shown. However Mectizan kills only the baby worms in the body, not the adults, who can continue to produce off-spring for 14 years. Work is underway to develop a drug which will eradicate the adult worms.