Key populations, or key populations at higher risk, are groups of people who are more likely to be exposed to HIV or transmit it and whose engagement is critically important for a successful HIV response. In all countries, key populations include people living with HIV. In most settings, men who have sex with men, transgender people, people who inject drugs and sex workers and their clients are at higher risk of exposure to HIV than other groups. However, each country should define the specific populations that are key to their epidemic and response based on the epidemiological and social context. UNAIDS considers gay men and other men who have sex with men, sex workers and their clients, transgender people and people who inject drugs as the four main key population groups. These populations often suffer from punitive laws or stigmatizing policies, and they are among the most likely to be exposed to HIV. Their engagement is critical to a successful HIV response everywhere—they are...
