Introduction to Epidemiology 6th Edition by Ray M Merrill

Exercise 8

Snow suggested several reasons for the failure of contaminated water to produce disease in all who consume it. Why is it that not everyone became sick or died when they consumed the cholera causing bacterium Vibrio cholerae?

Step 1 of 2

Cholera is contagious disease which is caused by the effluvia present in the water and food. It mainly infects the alimentary canal, and is caused by the various strains of Vibrio cholerae. V. cholerae releases endotoxins, called as cholera toxin, once it enters the alimentary canal. This toxin is the main cause of diarrhea and vomiting.

The most horrific cholera outbreak took place in Broad Street, London, in the year 1854.

People who consumed water from the common pump were attacked by cholera. People residing in adjacent regions were also attacked by cholera. The deceased were reported to have consumed water from Broad Street in one form the other. Many local coffee shops used the pump water and served it at dinner time.