Cholera infections are ten times higher than the number of cases reported to the World Health Organisation (WHO), according to new estimates of the global disease burden. Cholera is caused by eating food or drinking water contaminated with the Vibrio cholera bacterium. The disease causes watery diarrhoea and severe dehydration that can be fatal. In a study published in the Bulletin of the World Health Organisation this month (1 March), researchers from the International Vaccine Institute, in South Korea found a more accurate estimate of the global cholera burden is nearly three million cases a year, and around 93,000 deaths - the majority in children under the age of five.