3.8 Key points

The investigation requires rigorous preparation.

The effectiveness of the response depends primarily on how quickly the outbreak is identified.

The case definition should be simple, clear, standardised and constant throughout the entire period.

Laboratory confirmation should be done on the first 5 to 10 cases, at a minimum.

Demographic data should be reliable and the choice, made by consensus, should be justified.

Describe the epidemic in terms of Time - Place - Person: scale and evolution, geographic spread, groups at risk.

The definition of an outbreak varies according to the context.

For each area, assess the outbreak’s severity and potential for spread using the analysis table.

Assess the initial actions taken to manage the outbreak and immediately step-up, if necessary, during the investigation phase (assessment/action).

Write an accurate, concise investigation report and distribute it.