HIV-indicator-condition-driven HIV testing: clinically effective but still rarely implemented.

In the UK, outcomes for people living with HIV are excellent. However, a quarter of those living with HIV do not know their status, and almost half are diagnosed late. Strategies to broaden HIV testing are needed. HIV indicator conditions are those thought to be associated with HIV infection because they share risk factors (eg viral hepatitis) or because they arise as a result of early or late immunodeficiency (eg bacterial pneumonia, Kaposi's sarcoma). They comprise all AIDS-defining conditions, but also many non-AIDS-defining conditions spanning the spectrum of medicine. Patients presenting with indicator conditions should routinely be offered an HIV test. This approach is likely to be clinically effective, because knowledge of HIV status is essential in the management of many conditions. It is cost effective if the prevalence of HIV infection is greater than 0.1%. The strategy removes the need for risk assessment, and is acceptable to patients and healthcare practitioners. If broadly implemented, it is likely to be effective at a public health level, and will help to reduce both undiagnosed HIV and late diagnoses of HIV. Here we review the emerging evidence base that supports the value of routine HIV testing in indicator conditions.