A parasitic disease which affects more than 200 million of the world’s poorest people is transmitted between humans and their livestock through "hybrid" flatworms, a UK-funded project has found.

Schistosomiasis, a chronic disease caused by parasitic flatworms which leads to an intestine or urinary tract infection, is common in communities without access to safe drinking water and sanitation.

While efforts to control the disease have been partially successful, they have been limited by the flatworms ability to rapidly adapt and evolve.

But in an announcement on Monday, scientists working in West Africa said that growing hotspots of the disease are driven by the emergence of highly infectious "hybrid" parasites, formed when species of schistosome from both livestock and humans combine.

The research finding, which the World Health Organisation have incorporated into treatment guidelines, will have a significant impact on stemming the transmission and spread of the disease.

“That this species of really nasty parasitic worm can survive in livestock as well as humans is really unexpected,” said Prof Charlotte Watts, Chief Scientific Adviser at the Department for International Development (Dfid). “Before, we assumed [disease transmission] was always from a cycle between worms.

“This finding is really important in terms of public health and demonstrates the huge potential for science to really make a difference,” she added.