True or false: An epidemic is the occurrence in a community or region of cases of illness clearly in excess of expectancy.

An epidemic is indeed defined as the occurrence of cases of illness in a community or region that significantly exceeds the expected level based on historical data. This definition highlights how an epidemic represents not just a higher incidence of a disease, but rather an unusual increase that is not typical for that specific area or population at a given time.

When a specific disease suddenly appears more frequently than anticipated, it suggests a disruption in the normal pattern, prompting public health responses to investigate, control, and prevent further spread. This clear distinction from normal levels serves as a critical basis for identifying and categorizing an epidemic, making the true statement about the nature of epidemics accurate.

Other options don’t directly define what constitutes an epidemic. While needing verification might be applicable in some contexts, it doesn’t change the fundamental definition of an epidemic itself.