Acute dehydration caused by diarrhoea is one of the most common causes of death amongst children in low and middle-income countries. A new study from the Swedish medical university Karolinska Institutet now shows that almost half a billion cases of child diarrhoea a year could be treated if they all received treatment equal to the best standards in their home countries.

"It's unacceptable that so many children risk death when we know that there's simple, and cheap, fluid replacement treatment available," says Dr Birger Forsberg, one of the researchers behind the study.

The study was based on the results of 93 different household surveys in 55 low- and middle-income countries between 1990 and 2005. The researchers made particularly close study of data on the incidence and treatment of diarrhoea in children up to the age of five, and socioeconomic differences. One of their findings was that the treatment of diarrhoea with fluid replacement - oral rehydration - was 30 per cent more common in the wealthiest 20 per cent of households than it was in the poorest…