Three ways of reporting disease occurrence in a population?

• A. Host Traits, Time, Place
• B. Incidence, Prevalence, Mortality
• C. Severity, Duration, Onset
• D. Age, Sex, Breed

Answer: (A)

Describing disease occurrence in a population is organized by who is affected, where it occurs, and when it happens. The three pieces—host traits (the person dimension), place, and time—together capture the full pattern of disease in a population. “Host traits” include characteristics like age, sex, or breed that identify who is most affected. “Time” reveals temporal patterns such as seasonality, trends, and outbreak periods. “Place” shows geographic distribution, helping to spot clusters or regional differences.

This is why the correct choice is the best fit: it explicitly pairs host traits with time and place, covering the three dimensions used to report and analyze disease occurrence. The other options describe different concepts: incidence, prevalence, and mortality are measures of disease frequency rather than a descriptive framework; severity, duration, and onset are attributes of the disease rather than how occurrence is reported; and age, sex, and breed are host traits but omit the time and place dimensions. An example would be describing a disease outbreak by the affected animals’ ages and breeds (host traits), where the cases are occurring (place), and when the outbreak began and peaked (time).