Cholera
Cholera (Gr. chole = bile) is a severe water-borne diarrheal disease frequently occurring in developing countries. It is caused by Vibrio cholerae, a gram-negative curved bacillus bacterium, transmitted almost exclusively via contaminated water, food, etc. Two biotypes of V. cholerae have been recognized: classic and E1 Tor. Classic biotype has been virulent before 1961. In 1961, the E1 Tor biotype emerged as an important cause of cholera pandemics. However, in 1992 a newly identified strain V. choleras O139 emerged in Asia. In Calcutta (India), strain O139 of V. cholerae displaced E1 Tor V. cholerae strain O1 (the causative agent of seventh pandemic, an event that has never happened in the recorded history of cholera).

The sewage must be treated before disposal and proper disinfection of water supplies must be observed to prevent the outbreak of cholera. The immediate treatment of the disease is the oral rehydration therapy with NaCl plus glucose to estimate water uptake by the intestine. The antibiotics of choice are tetracyclin, trimethoprim-sulfamethoxazole or ciprofloxacin. The killed vaccine of cholera can be taken as prophylactic

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