Which term refers to a one-time exposure where all exposed become infected at roughly the same time, producing a single epidemic peak?

• A. Continuous Exposure
• B. Epidemic
• C. Single Exposure
• D. Multiple Exposure

Answer: (C)

A single, time-limited exposure leads to a point-source outbreak, with cases clustering in a narrow time window. When exposure happens once and nearly everyone exposed gets infected, the onset of illness tends to pile up after roughly one incubation period, producing a rapid rise to a single peak and then a decline as the outbreak runs its course. This pattern contrasts with continuous exposure, which stretches cases over a longer period and often flattens the curve, or with multiple exposures, which can create more than one peak. An epidemic is a broad term for a widespread outbreak and doesn’t specify how exposure occurred, so it doesn’t capture the single-peak pattern.