Cholera is an acute infection of the small intestine that is a particular problem in developing countries where access to clean drinking water and hygiene measures are poor. The disease causes severe diarrhea and vomiting leading to dehydration. Children and the elderly are at particular risk of rapidly developing and succumbing to the dehydration caused by cholera.
Over the last century, the number of cholera cases and deaths due to cholera have steadily declined, mainly due to improvements in sanitation and water hygiene. In England for example, no cases of cholera have originated in the country since 1893 and those that have been reported have been caught abroad.
Some of the regions where cholera is still a major health threat include:
Sub-Saharan Africa or the countries south of the Sahara desert
Some parts of the Middle East
South and south-east Asia including India and Bangladesh
Some parts of South America
In these regions, cholera is not a regular occurrence but may sometimes occur as outbreaks, especially during the summer season, natural disasters, wars or civil disorders. The outbreaks are almost always due to overcrowding of people living in poor conditions and with a lack of access to clean drinking water.
Cholera was first seen to spread as a pandemic to different parts of the world from the Indian subcontinent in 1817. The current pandemic originated in Sulawesi, Indonesia in 1961 and was caused by the El Tor biotype of the Vibrio cholerae serotype O1. It began to spread rapidly to other countries in Asia, Europe and Africa and even to Latin America in 1991.
Following this was the identification of a new strain called Vibrio cholerae O139 Bengal that caused outbreaks in India and Bangladesh in 1992. This strain is still confined to Asian countries.
Reviewed by Sally Robertson, BSc