Introduction to Epidemiology 6th Edition by Ray M Merrill

Exercise 15

“As the epidemic advanced, the disproportion between the number of cases in houses supplied by the Southwark and Vauxhall Company, and those supplied by the Lambeth Company, became not quite so great. . . .” From an epidemiological point of view, why was this so? Give detailed epidemiological reasoning and discussion addressing person, place, and time issues.

Step 1 of 2

Cholera is contagious disease that is caused by a gram negative bacterium Vibrio cholerae. It is generally transmitted through contaminated food and water. The main route of entry is the fecal-oral route. Endotoxins released by vibrio cholerae mainly infect the alimentary canal and caused watery diarrhea, muscular spasms and vomiting. Cholera toxin draws water from blood which causes severe diarrhea. As a result of this water and electrolyte imbalance takes place in the body. Treatment includes administration of ORS (Oral Rehydration Solution), Zinc supplements and antibiotics like azithromycin or doxycycline.

London was free from cholera from 1849 to 1853. Then an important change in the water supply that supplied to several districts of south of London, took place. The Lambeth Company moved from Hungerford Market to Thames Diton. This shift in the company resulted in supply of water free from any London waste. Hence, the houses that were supplied by only Lambeth Company did not report any attacks of cholera.