Case study: Over 30 children younger than 3 years of age developed gastroenterit
ID: 89195 • Letter: C
Question
Case study: Over 30 children younger than 3 years of age developed gastroenteritis after visiting a local water park. These cases represented 44% of the park visitors in this age group on the day in question. Older individuals were not affected. The causative agent was determined to be a member of the bacterial genus Shigella. The disease resulted from oral transmission to the children.
Based only on the information given, can you classify this outbreak as an epidemic? Why or why not? If you were an epidemiologist, how would you go about determining which pools in the water park were contaminated?
Explanation / Answer
Yes, the given case of outbreak of gastroenteritis affecting 44 % of the park visitors in a short span of time should be considered as epidemic. The rapid spread of infectious disease to a large number of people in a given population within a short period of time is termed as disease outbreak or epidemic disease. In this case 44% of the park visitors of the age group below 3 years became ill. This may have occurred from contaminated recreational water use including swimming pools, water slides and wave pools. As an epidemiologist a decision to conduct field investigation to find out which pools in the water park are contaminated after this acute outbreak should be done. In such situations epidemiologists follow a systematic approach which is ‘quick and clean’ without missing important steps. The scheme of investigative steps followed by an epidemiologist after such outbreak is as under:- Framing a well- designed field work Establishment of the existence of an outbreak Verification of diagnosis Constructing a working case definition Finding of cases systematically and then record information Performing descriptive epidemiology Developing of hypothesis Evaluating the hypothesis epidemiologically If necessary refining and reevaluating of hypothesis Comparing with laboratory findings Implementing control and prevention measures Maintaining surveillance and communicate the findings