Scottish scientists claimed that arsenic contamination of water supplies may have led to the deaths of people in India from leishmaniasis, the world's second-largest parasitic killer, despite advances in drug treatments.
Arsenic contamination of water supplies may have played a significant role in the development of widespread resistance in the India to an important drug used to treat leishmaniasis, they say.
Visceral leishmaniasis infects around half a million people across the world every year and close to one-in-ten of those die, a release by the University of Dundee and Aberdeen said today.
One of the main treatments for the disease is a group of drugs known as antimonial preparations.
However, by the end of the 20th century their effectiveness in treating the disease in Bihar, which houses 90 per cent of India's leishmaniasis victims, was so low that use of the drugs was no longer recommended.
Now researchers at the Universities of Dundee and Aberdeen have concluded that arsenic contamination of the water supply may have played a significant role in building resistance to the drugs.
"The Indian subcontinent is the only region where arsenic contamination of drinking water coexists with widespread resistance to antimonial drugs which are used to treat visceral leishmaniasis," said Professor Alan Fairlamb, of the University of Dundee.
"The water supply in Bihar has been found to be affected by contamination from naturally occurring arsenic in the ground water. What we have been able to show through experiments is that arsenic contamination of water can build resistance in Leishmania parasites to antimonial treatments, he said.
"This is important as we need to be sure of why resistance to drugs develops," he added.
Leishmaniasis is a neglected disease that has a devastating effect across the developing world and there is a desperate need for better drugs to treat it.
Meghan Perry, a Wellcome Trust-funded clinical PhD student working on the project, has also carried out field research in Bihar.
Meghan said arsenic contamination of the groundwater is a serious issue in Bihar. Many villagers continue to drink arsenic contaminated water as they have no alternative.
Knowledge of the dangers of arsenic pollution is low and mitigation projects are not reaching all of those in need.
The research is published in a paper in the journal PNAS (Proceedings of the National Academy of Sciences of the United States of America).
