What term is used to describe the number of new cases of a disease during a specified period divided by the population at risk per 100,000 population?

The correct term that describes the number of new cases of a disease during a specified period divided by the population at risk per 100,000 population is incidence. Incidence is a key epidemiological measure that focuses exclusively on new cases occurring in a defined population over a specific timeframe, allowing public health professionals to understand the rate at which a disease is spreading.

This concept is critical in public health as it provides insight into the risk of developing the disease and helps in identifying trends over time. It is different from prevalence, which encompasses all cases (both new and existing) within a population at a given time. Mortality addresses deaths caused by a disease rather than the occurrence of new cases, while case-fatality ratio reflects the proportion of deaths among diagnosed cases of a particular disease. Each of these terms serves a different purpose in epidemiology, but incidence specifically focuses on new occurrences, making it the correct choice here.