What does an epidemic curve primarily illustrate?

• A. Graph of cases by time
• B. Distribution of cases by geographic location
• C. Severity of illness by case
• D. Source of exposure for the outbreak

Answer: (A)

An epidemic curve focuses on the time dimension of an outbreak. It is a graphic representation of the number of new cases that occur each day (or week), showing how the outbreak starts, rises, peaks, and subsides. This time-based view helps you understand the pace and pattern of transmission and can hint at the outbreak’s stage and possible incubation periods.

Distributions by geographic location would be shown on a map or a chart by place, not by time. Severity by case would require data on how ill each case is (mild to severe to fatal). The source of exposure pertains to tracing where cases came from rather than the timing of when they occurred.