Field epidemiology the application of epidemiology under a set of general conditions:
The problem is unexpected
A timely response may be demanded
Travel to and work in the field is required by epidemiologists to solve the problem
The investigation time is likely to be limited because of the need for a timely intervention
Field investigations involving acute problems may differ from conventional epidemiologic studies in three important ways 1. Field investigations often do not start with a clear hypothesis 2. Acute problems involve an immediate need to protect the public and resolve the concern 3. Field epidemiologists must decide when the available information is sufficient to take appropriate action
Steps in field investigation 1. Establish the existence of an epidemic (or outbreak) a. Attack rates are appropriate statistics for investigating disease outbreaks because they describe rapidly occurring new cases of disease in a well-defined population over a limited time period. b. Attack rates are usually calculated by person characteristics (e.g., age, sex, race/ethnicity, and occupation) in order to identify high-risk groups. 2. Confirm the diagnosis c. Assessment of the clinical findings should be done to assure correctness and reliability of the findings d. Clinical diagnosis by appropriately trained individuals e. Laboratory diagnosis 3. Establish criteria for case identification f. Standard clinical criteria (what) g. Loose case definition vs. strict case definition h. A case may be further characterized by i. Who ii. When iii. Where 4. Search for missing cases i. Investigation may include iv. Physicians v. Clinics vi. health maintenance organizations vii. hospital emergency rooms viii. public health clinics ix. migrant health clinics x. and