What is the term for the number or proportion of cases of a particular disease present in a population at a given time?

The term that indicates the number or proportion of cases of a particular disease present in a population at a given time is prevalence. This measurement provides an understanding of how widespread a disease is within a particular population and is typically represented as a percentage or ratio.

Prevalence considers all existing cases—both new and pre-existing—during a specified time period, making it a crucial metric for public health and epidemiology. It helps to assess the burden of a disease on society, guiding healthcare resource allocation and informing health policies.

In contrast, incidence refers specifically to the number of new cases that arise in a population over a given period, focusing on the transition from a non-diseased to a diseased state. Mortality rate relates to the frequency of deaths within a population, rather than the presence of cases. Endemic level pertains to the constant presence and/or usual prevalence of a disease in a geographic area, which is more about the long-term situation rather than the snapshot provided by prevalence.