Introduction to Epidemiology 6th Edition by Ray M Merrill

Exercise 2

What are your observations as to the source of the contamination of the well water with Shigella sonnei that caused the outbreak? Give two possible sources for the pathogen getting into the water supply: (1) direct and (2) indirect.

Step 1 of 2

The water in the well of the school of Stockport in Iowa was contaminated by bacterium named as Shigella sonnei. The source of contamination may be the ground water that was seeping into the well. This ground water may contain this bacterium and then it contaminated the whole well. This causes a serious problem as it cause the disease Shigellosis in the students and faculty members of the school.

The second contamination was through the soil in which this bacterium might be present. This soil may contain this bacterium and through wind and water it reaches to the well. The third contamination source was the sewer system, from which the bacterium reaches the well. Another source was also the rainwater that was contaminated with this bacterium.

Some vectors like fomites and flies also carried this Shigella bacterium and contaminated the well water.