The different stages of an HIV epidemic
How the HIV epidemic develops may differ within each country or region of the world.
In general we speak of three kinds of epidemics:
- Generalised epidemic: HIV prevalence among adults exceeds 1% of the general population and transmission is mostly heterosexual.
- Concentrated epidemic: HIV is concentrated among groups with behaviour that exposes them to a high risk of HIV infection.
- Low-level epidemic: HIV prevalence among adults is less than 1%, HIV infections are present among different groups within a population.
In most cases, an epidemic develops from a concentrated epidemic into a generalised epidemic.
Special target groups
Prevention and intervention programmes should be adapted to the current situation in a country or region. However, when developing intervention programmes it’s important to address not only high-risk and vulnerable groups, or only the general population.
Programmes need to target high-risk and vulnerable groups as well as the general public.
High-risk groups tend to have a higher prevalence of HIV infection than that of the general population because they engage in behaviour that puts them at higher risk of becoming infected. High-risk groups are: drug users, sex workers, men who have sex with men, and prisoners. These are some of society’s most marginalised and discriminated groups.
Vulnerable groups are individuals, groups or communities that are unable to control their own risk of infection due to poverty, gender inequality, conflict or natural disasters. Vulnerable groups that are often taken into account for prevention programmes are: women, orphans and vulnerable children, and adolescents
Different responses
The response to HIV and AIDS within a specific country or region should be adapted to the current situation.
There can be a focus on three categories:
- Prevention programmes
- Treatment and care
- Reducing the impact (mitigation activities)
A response is the most effective when it consists of a combination of simultaneously implemented interventions.
In this section you will find more detailed information on different target groups as well as possible responses. The information is taken from the 2006 UNAIDS report on the global AIDS epidemic. For more specific and in-depth information please click on the links or read the relevant articles.
