Efforts to eradicate a tropical disease which can result in three-feet-long worms bursting out of people's flesh were boosted by a £50m UK cash injection yesterday.

The aid package, announced by International Development Minister Douglas Alexander, is aimed at eradicating Guinea worm within just five years. It will pay for health workers, water filters and safe water supplies in South Sudan, Nigeria, Ghana, Niger and Mali - the countries which still harbour the disease.

Infected fleas in dirty drinking water cause the condition - which leaves victims facing up to a year of highly-painful swelling and infected skin as the worm emerges, usually from arms, legs or stomach.

Other parasitic and bacterial tropical diseases targeted by the aid are river blindness, disabling elephantiasis, blinding trachoma and bilharzia - an infection that can be fatal.

Mr Alexander said: "Building upon President Bush's announcement in March of $350m (£175m) and the G8 call in Japan, the UK is supporting the US president's efforts to control or eliminate several tropical diseases with a £50m funding boost.

"Around one billion people suffer from one or more painful, debilitating tropical diseases. Thirty years ago, scientific breakthroughs led to doctors eradicating smallpox by developing a vaccine.

"We don't need drugs to eradicate Guinea worm. The solution is simple. Protect water supplies from contamination by identifying and containing cases and in just five years, Guinea worm could be eradicated."

Professor David Molyneux, of the Liverpool School of Tropical Medicine said: "This funding will help towards alleviating the suffering of the poor through simple solutions to Guinea worm."