What is the definition of incidence in the context of disease?

Incidence is specifically defined as the number of new cases of a disease that occur in a specified population during a defined period of time. It is a measure that reflects the rate at which new cases are appearing in a population, making it essential for understanding the dynamics of disease spread and the effectiveness of interventions.

When assessing public health, understanding incidence helps in evaluating the risk of contracting a disease and the effectiveness of preventive measures. This differentiates it from measures like prevalence, which refers to the total number of existing cases (both new and old) in a population at a given time, hence highlighting the distinction in terminology.

Other choices present concepts related to disease but do not accurately define incidence: the first choice regarding the percent of existing cases describes prevalence, while the second choice relates to mortality rates, and the fourth option refers to the occurrence of chronic conditions rather than new infections or cases of a specific disease.