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Using an Epi Curve to Determine Most Likely Period of Exposure

What an Epi Curve Can Tell You

An epi curve is a visual display of the onset of illness among cases associated with an outbreak.

You can learn a lot about an outbreak from an epi curve, such as

  • The outbreak's time trend, which is the distribution of cases over time
  • Outliers, that is, cases that stand apart from the overall pattern
  • General sense of the illness magnitude
  • Inferences about the outbreak's mode of spread
  • The most likely period of exposure

In a point source outbreak of a known disease, you also can use the epi curve to identify the most likely time period of exposure that led to the outbreak. Knowing the period of exposure allows you to focus your search for the source of the outbreak.