Table 6.2.

Steps in the investigation and control of a potential outbreak

1.Establish case definition(s). 2.Confirm that the cases are ‘real’ (case confirmation). 3.Establish the background rate of disease (in order to confirm the outbreak and determine the scope of the outbreak geographically and temporally). 4.Case finding. 5.Examine the descriptive epidemiology of the cases (e.g. define the age, sex, home/overseas travel, occupation, attendance at events) and plot an ‘epidemic curve’ of time of onset of disease. 6.Generate a hypothesis regarding the source and route of exposure. 7.Test the hypothesis by case control, cohort or intervention studies and by epidemiologic typing of representative samples if indicated and if possible. 8.Collect and test potential sources of infection such as environmental surfaces, patients, personnel, iv fluids, etc. as indicated; consider epidemiologic typing to establish an epidemiologic link to cases. 9.Devise and implement control measures. 10.Review results of investigation or report on ongoing investigations to administration and staff; consider consultation with local public health officials. 11.Follow-up surveillance to evaluate efficacy of control measures; generate reports for administration and staff.