Cholera 霍乱是一种严重的流行病，150 年来它已经夺去了数百万人的生命。你了解它的症状和起源吗？ Cholera is a very serious intestinal ( 肠内的) infection caused by taking food or water polluted with the bacterium Vibrio cholerae. Most people infected with V. cholerae do not become ill, although the bacterium is present in their faeces ( 粪便) for 7-14 days. When illness does occur, about 80-90% of cases are of mild or moderate severity and are difficult to distinguish from other types of seriousdiarrhoea ( 腹泻). Less than 20% of those infected develop typical cholera with signs of moderate or severedehydration (脱水). During the 19th century, cholera spread repeatedly from its original source in the Ganges delta in India to the rest of the world, before falling back to South Asia. Six pandemics ( 大流行病) were recorded that killed millions of people across Europe, Africa and the Americas. The seventh pandemic, which is still ongoing, started in 1961in South Asia, reached Africa in 1971and the Americas in 1991. The disease is now considered to be endemic in many countries and the bacterium causing cholera cannot currently be got rid of from the environment. Cholera remains a threat in almost every developing country. The number of cholera cases reported to WHO during 2006rose greatly, reaching the level of the late 1990s. A total of 236,896 cases were reported in 52countries, including 6,311 deaths, an overall increase of 79% compared with the number of cases reported in 2005. This increased number of cases is the result of several major outbreaks that occurred in countries where cases have not been reported for several years. 本文来源：https://www.wddqw.com/doc/9ea20d6c32687e21af45b307e87101f69f31fb48.html