Which term refers to the total number of existing cases of a disease?

The term that refers to the total number of existing cases of a disease within a population at a specific point in time is prevalence. This measurement is crucial in public health as it provides a snapshot of the burden of disease and helps in understanding how widespread a health issue is in a given population. Prevalence includes both new and existing cases, allowing researchers and healthcare professionals to gauge the overall impact of the condition.

In contrast, incidence refers specifically to the number of new cases that occur in a defined population during a specified time period, which helps to assess the risk of developing the disease. Morbidity encompasses the state of being diseased or unhealthy, often measured by rates of illness or disability, but does not specifically quantify the total number of cases. Metaplasia describes a cellular change where one differentiated cell type is replaced by another, which is unrelated to the counting of cases of a disease.