Identifying a common source involves several steps:
1. Epidemiological Investigation: Epidemiologists first identify and confirm an outbreak by comparing the observed number of cases with the expected number. This involves collecting and analyzing data on the affected individuals.
2. Descriptive Epidemiology: This step includes characterizing the outbreak by time, place, and person. By doing this, patterns may emerge that suggest a common source.
3. Hypothesis Generation and Testing: Based on the collected data, hypotheses about potential common sources are generated. These hypotheses are tested through analytical epidemiology, such as case-control or cohort studies.
4. Environmental Investigation: This involves examining potential sources of exposure in the environment, such as food samples, water sources, or air quality tests.
