IGX

Dr Hirschhorn says there was disbelief something so simply could be so effective and outperform the carefully-dosed, hospital-administered IV therapy

"Its simplicity was its own enemy. But it took a long time; it took a very long time to convince paediatricians that this was safe, to convince them that you could get out there and reach mothers, reach the community directly."

The Lancet has described oral rehydration therapy as "potentially the most important medical advance" of the 20th century with UNICEF adding that no other medical innovation of the century "has had the potential to prevent so many deaths over such a short period of time and at so little cost".

Now the effectiveness is well known and it is used around the world administered by doctors in clinics as well as at home by parents of children.

But the World Health Organization (WHO) warns diarrhoeal disease is the second leading cause of death in children under five, and is responsible for killing around 760 000 children every year.