Lars Haukali Omland, Rebecca Legarth, Magnus Glindvad Ahlström, Henrik Toft Sørensen, Niels Obel

It has been suggested that targeted human immunodeficiency virus (HIV) testing programs are cost-effective in populations with an HIV prevalence >0.1%. Several indicator diseases are known to be associated with increased risk of HIV infection, but estimates of HIV frequency in persons with relevant indicator diseases are nonexistent. In a nationwide population-based cohort study encompassing all Danish residents aged 20-60 years during 1994-2013, we estimated the 5-year risk of an HIV diagnosis (FYRHD) after a first-time diagnosis of 147 prespecified potential indicator diseases. To estimate the risk of HIV diagnosis in the general population without any indicator diseases, we calculated the FYRHD starting at age 25, 35, 45, and 55 years. The risk in the male general population was substantially higher than the female general population, and the risk was lower in the older age categories. Individuals of African origin had a higher FYRHD than individuals of Danish origin. A number of diseases were identified with a FYRHD >0.1%, with infectious diseases, such as syphilis, hepatitis, and endocarditis, associated with a particularly high FYRHD. Other potential indicator diseases, such as most urologic, nephrologic, rheumatologic, and endocrine disorders were generally associated with a low FYRHD. Our study identified a large number of indicator diseases associated with a FYRHD >0.1%. These data can be used as a tool for planning targeted HIV screening programs.