The UK’s pledge is part of a global push to try to wipe out ten awful diseases that can be easily prevented, but have been overlooked because they do not affect people in rich countries.

One of the diseases, elephantiasis, is spread by mosquitoes and causes the legs and feet to massively swell up. It is very painful and, in some cases, means that people are unable to walk.

Another of the diseases, onchocerciasis – also known as river blindness – causes worms to grow inside people, spreading larvae which live in the skin and cause intense itching and an eye disease that can lead to blindness.

 “The world has come together to end the neglect of these horrific diseases, which needlessly disable, blind and kill millions of the world’s poorest,” said Stephen O’Brien, the International Development Minister.

He recently visited Tanzania to meet people benefiting from UK aid to prevent these tropical diseases.