Home › NCK Licensing Exam (Nursing) › Public Health › Epidemiology and Outbreak Investigation › In theory, what shape should the epidemic curve …
In theory, what shape should the epidemic curve take for a disease spread from person to person?
AOne tall peak followed by a long flat tail
BA single plateau lasting several weeks in all
CProgressively taller peaks one incubation apart
DAn irregularly jagged curve with no clear peaks
Answer & Solution
Correct answer: C. Progressively taller peaks one incubation apart
1. In a propagated epidemic each generation of cases infects the next, so numbers grow from generation to generation.
2. Each generation is separated from the last by roughly one incubation period.
3. The theoretical curve is therefore a series of progressively taller peaks spaced one incubation period apart.
4. Few real outbreaks show this classic pattern cleanly, so the shape is a teaching ideal rather than a guarantee.
5. A plateau belongs to a continuous common source epidemic, and a jagged curve to an intermittent one.
6. A single tall peak with a long tail is the point source shape, which needs only one exposure event.
_Source: CDC Principles of Epidemiology in Public Health Practice, 3rd Edition, section Interpreting an Epidemic Curve_
Related questions
At a banquet the attack rate was 65.4% among people who ate beef and 11.4% among those whoWhich study design suits an outbreak of gastroenteritis among wedding guests, where a compCommunicating the findings of a completed outbreak investigation usually takes which two fAfter control measures have begun, active surveillance is continued mainly to answer whichControl and prevention measures are numbered eleventh in the conceptual sequence of an outVerifying the diagnosis early in an outbreak investigation serves which two purposes?A health department must judge whether an increase in reports of a notifiable disease is aInvestigators telephone and visit hospitals and clinics to collect information on any furt