Another important pathophysiological feature of V. On excretion into the environment, it has been found that the bacteria undergo a period of 24 hours of hyper-infectious activity and are more likely to be transmitted in a human-to-human fashion, explaining the explosive nature of cholera epidemics. Cholera toxin is then secreted and eventually endocytosed by the intestinal epithelial cells, altering the electrolyte channels, and resulting in endoluminal fluid loss rich in chloride, bicarbonate, sodium, and potassium. cholerae requires a comparatively high infectious dose (10^8). cholerae's highly effective motility and ease of attachment to the intestinal wall. Small intestine colonization is highlighted by V. cholerae strains, ease of travel and constant migration of possibly infected individuals have raised serious public health concerns. Although safe drinking water and advanced sanitation systems have made cholera a treatable and limited illness in Europe and North America, new V. Recently, cholera has continued to affect vulnerable communities like post-earthquake Haiti (2010), Iraq, and Yemen, where natural disasters, refugee movement, war, and conflict increase the risk of infection and outbreaks. Although widely under-reported, the World Health Organization estimates a total of 2.8 million cases with 91,000 deaths annually. The seventh pandemic has been ongoing since 1961, reaching South America and most of the Western Hemisphere in 1991. cholerae originated in the Indian subcontinent and caused six pandemics from 1827 through 1923. Currently, it is endemic in 69 countries including Asia, Africa, and the Americas with 1.3 billion people at risk, Sub-Sahara Africa being the worst. In developed countries, it is seen sporadically. Ĭholera is endemic to world regions with poor water, sanitation, and hygiene infrastructures, such as Sub-Saharan Africa and regions of the Middle East. cholerae is also found as a free-living organism in brackish water and can survive in fresh or saltwater, which explains the occasional infections via shellfish. cholerae, and transmission is by the fecal-oral route. However, V. Ĭholera is transmitted through contaminated water and/or food especially in vulnerable communities affected by natural disasters, war, and famines. Recently, there has been an increased recognition for the role that non-O1 and non-O139 serogroups may be playing in diarrheal illness and gastroenteritis. In 1992, serogroup O139, or Bengal, emerged as another epidemic variant of V. Until recently, the disease was caused by only 2 of these serotypes, Inaba and Ogawa, and 2 biotypes, classical and El Tor, of toxigenic serogroup O1. It has hundreds of serogroups that include pathogenic and non-pathogenic strains. cholerae is a highly motile, comma-shaped gram-negative bacteria with a single polar flagellum.
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