Short answers, pulled from the story.
Cholera is caused by the bacterium Vibrio cholerae, which infects the small intestine. It spreads mainly through water or food contaminated with human feces containing the bacteria; undercooked shellfish is a common source, as V. cholerae accumulates in planktonic crustaceans eaten by oysters.
The primary symptoms are profuse watery diarrhea, often described as "rice water" in appearance with a fishy odor, and vomiting. An untreated person may produce ten to twenty litres of diarrhea a day, leading to severe dehydration, sunken eyes, cold clammy skin, muscle cramps, and, without treatment, death.
The primary treatment is oral rehydration therapy using slightly sweet and salty solutions, with rice-based solutions preferred. Severe cases require intravenous rehydration with Ringer's lactate. Antibiotics such as doxycycline can shorten the course of the disease but are recommended by WHO only for those with severe dehydration.
The WHO has prequalified three oral cholera vaccines: Dukoral, Sanchol, and Euvichol. Dukoral has an overall efficacy of about 52% in the first year and 62% in the second year. In the United States, the FDA-approved vaccine is Vaxchora, a single-dose oral live vaccine effective for adults aged 18-64 traveling to cholera-affected areas.
John Snow (1813-1858), a physician working in England, identified contaminated water as the source of cholera transmission in 1854 through two pioneering field studies in London. His map of cholera cases was the first recorded instance of epidemiological tracking, and he is often called the Father of Epidemiology.
Seven cholera pandemics have occurred since the early 19th century. The seventh and most recent pandemic began in 1961 in Indonesia, driven by a strain nicknamed El Tor. It has continued to the present day, with the worst recent outbreak occurring in Yemen, where 93% of the world's 923,037 reported cholera cases in 2019 were recorded.