. EPIDEMIOLOGY Cholera continues to be an important public health problem among many communities It is one of the oldest diseases affecting humans. It is caused by the gram-negative bacteria Vibrio cholerae. About 20% of those who are infected develop acute, watery diarrhoea – 10–20% of these individuals develop severe watery diarrhoea with vomiting Can cause as high as 20 to 50% mortality if case management is not adequate. Conversely, the death rate can be low (