In Europe many patients infected with HIV remain undiagnosed, although this percentage varies between 15-80% across the continent. In the UK it is estimated to be 27%. Undiagnosed HIV results in increased morbidity and mortality and reduced treatment response, as appropriate health interventions are delayed. It also has adverse public health implications, with those individuals unaware of their HIV status being more likely to transmit the virus.

An important public health issue is how to diagnose more individuals with HIV earlier in the course of their infection. In the US, the Centre for Disease Control and Prevention (CDC) has introduced testing guidelines whereby all individuals are tested, unless they object, at any point of contact with the healthcare system - the "opt-out" testing guidelines.

At the "HIV in Europe" Conference held in November 2007, the consensus, which included patient and public involvement, was that such an approach would not be suitable for Europe. The Conference recommended further development of focused HIV testing in patients presenting with certain clinical conditions and diseases - the "indicator disease'' testing guidelines.

Cost effectiveness analyses suggests cost savings if a screened population has an HIV prevalence of at least 1%, although this rate may be as low as 0.1%. However, there is very little - if any - evidence regarding HIV prevalence for certain conditions and diseases in specific and easy to identify sections of society. The focus of attention is on those conditions and diseases which occur more frequently in individuals known to be infected with HIV.

The aim of this study is to assess HIV prevalence for several diseases and conditions, within a specific segment of the population not yet diagnosed with HIV, who present for care with that specific disease or condition. These conditions have been selected as they occur frequently in individuals already diagnosed with HIV infection. This is a pilot study to inform phase two, which will involve more diseases and conditions with a wider participation of centres across Europe.

Inclusion criteria

• Aged 16 years and over

• Presenting for care with one of the indicator diseases or conditions:

  • A sexually transmitted disease
  • Malignant lymphoma
  • Cervical or anal dysplasia or cancer
  • Unexplained leukocytopenia or thrombocytopenia lasting at least 4 weeks, or hypergammaglobulinaemia
  • Seborrheic dermatitis or exanthema

• sub-study - consents to providing additional information

Exclusion criteria

• Known HIV positive
• sub-study - declines to consent for additional information to be collected

Adults (16 years and over), not known already to be HIV-positive, presenting for care in designated healthcare settings with one of five "indicator diseases." Sequential patients will be offered HIV tests, and if they accept, asked to provide additional information via focussed interview (sub-study).