Which has an incubation period of less than a week: March 2010

Ans. A: Cholera Cholera is an acute diarrhoeal infection caused by ingestion of the bacterium Vibrio cholerae. Transmission occurs through direct faecal-oral contamination or through ingestion of contaminated water and food. The disease is characterized in its most severe form by a sudden onset of acute watery diarrhoea that can lead to death by severe dehydration and kidney failure. The extremely sho incubation period - two hours to five days - enhances the potentially explosive pattern of outbreaks, as the number of cases can rise very quickly. About 75% of people infected with cholera do not develop any symptoms. However, the pathogens stay in their faeces for 7 to 14 days and are shed back into the environment, potentially infecting other individuals. Cholera is an extremely virulent disease that affects both children and adults.