The global dimensions of cholera

The global dimensions of cholera Cholera remains among the most feared infectious diseases. The fi rst six pandemics of cholera, beginning in 1817, were major public health emergencies, infl icting high morbidity and mortality across the world. Today we continue to battle with the seventh pandemic that began in 1961 and shows no sign of abating. Of particular concern is the spatially and temporally different epidemiological pattern of Vibrio cholerae O1 biotype El Tor cholera. Accompanying these worrying signs is the emergence and spread of V. cholerae O139 Bengal in parts of Asia since the early 1990s. Cholera is behaving differently and is serving as a barometer of the unhealthy global changes around us. C holera remains one of the most feared infectious diseases in public health. It is an acute bacterial infection of the intestine caused by the ingestion of food or water contaminated by certain strains of the Vibrio cholerae organism. V. cholerae produces enterotoxins (toxins which act in the gastrointestinal tract) whose actions on the mucosal epithelium is responsible for the characteristic symptoms of the disease, namely acute watery diarrhoea and vomiting. In the most severe cases, cholera is one of the most rapidly fatal illnesses known, due to severe dehydration or water loss. If left untreated, mortality from " classical " cholera can be 50%. A healthy person may become hypo-tensive within an hour of the onset of symptoms and may die within 2-3 hours although more usually death may come within a day or so. Death in this way prompted the French to call cholera mort de chien (the dog's death). With effective treatment, through fl uid and electrolytes replacement, mortality can be reduced to less than 1%. Affected individuals are highly infectious, contaminating water and food sources that they come into contact with. Therefore, the appearance of epidemic forms of cholera is treated as a public health emergency. Until 1817, cholera largely remained a disease of South Asia. Epidemics of cholera-like diseases on the Indian subcontinent have been recorded from the early sixteenth century, and the history of the disease goes back much further (based on references to deaths from dehydrating diarrhoea by Hippocrates and Sanskrit writings). From the nineteenth century onward, cholera spread to other parts of the world in seven pandemic waves. The fi rst six pandemics of " classical " cholera left in their wake high levels of morbidity and mortality, …