Core concepts for HIV epidemiology

The following concepts are important to understand when working with HIV statistics:

  1. It is not necessary to memorize all the numbers. What is important is to note whether the numbers are large relative to the identified population (or small). It is also important to follow trends to see if numbers are increasing (or decreasing). Trends can also be inferred if at least three or more sets of data over time are available.

2. Understand the difference between prevalence and incidence.

HIV prevalence is a measure of the total proportion of individuals in a population who are HIV infected.

HIV incidence is a measure of the rate of new HIV infections occurring in a population (usually over a year).

3. When interrogating the numbers, it is always important to clearly describe the HIV sub-population group being investigated. Obviously, HIV rates differ between the different groups.

Sub pops table