The case for expanding the definition of 'key populations' to include high-risk groups in the general population to improve targeted HIV prevention efforts.

Background: Two additional key populations within the general population in South Africa (SA) that are at risk of HIV infection are black African women aged 20 - 34 years and black African men aged 25 - 49 years.

Objective: To investigate the social determinants of HIV serostatus for these two high-risk populations.

Methods: Data from the 2012 South African National HIV Prevalence, Incidence, and Behaviour Survey were analysed for black African women aged 20 - 34 years and black African men aged 25 - 49 years.