Recent efforts have been directed towards introducing universal HIV testing for asymptomatic individuals considered at high risk of infection.10 UK national guidelines recommend routine HIV testing for general medical admissions and newly registering general practice patients in areas where HIV prevalence exceeds 2 per 1000 among 15- to 59-year-olds.1 However, many patients may present symptomatically.11 Evidence suggests that up to one-third of newly diagnosed patients may have had multiple encounters with primary care services,12 with symptoms that, in hindsight, were clearly related to HIV.13,14 Yet the clinical diagnosis of HIV-related conditions in primary care is complex, as many of the presenting signs or symptoms associated with HIV are commonly seen in people without it.
The UK HIV guidelines identify 37 unique clinical indicator conditions for adult HIV infection (Box 1), whose presence should prompt the offer of an HIV test.10 While each of these indicator diagnoses has been reported in HIV-infected patients, few data currently exist to show their predictive value in identifying undiagnosed HIV. A predictive tool, based on patient presentation in primary care with any of the 37 clinical indicator conditions, has the potential to improve the detection of the symptoms most predictive of HIV infection. This could facilitate the implementation of targeted HIV testing in primary care settings where HIV testing is not routinely offered but where patients presenting with one or more indicator conditions are regularly encountered.
This study used anonymised patient records from The Health Improvement Network (THIN) general practice database, to identify the symptoms and clinical diagnoses associated with increased risk of HIV infection, in order to develop a predictive model to identify the relative importance of these factors in identifying HIV cases.
How this fits in
Up to one-third of patients newly diagnosed with HIV may have had multiple encounters with primary care services, with symptoms that were, in hindsight, clearly related to HIV infection. National HIV guidelines identify 37 unique clinical indicator conditions whose presence should prompt the offer of an HIV test, but few data currently exist to show the predictive value of these conditions in indicating undiagnosed HIV. This study found the conditions most strongly associated with HIV diagnosis were bacterial pneumonia, oral candidiasis, and herpes zoster, suggesting that patients presenting in primary care with these conditions should be routinely offered an HIV test. However, only a minority of HIV patients show any indicator conditions prior to diagnosis, and most are asymptomatic. Nevertheless, many missed opportunities for earlier diagnosis may exist where patients present symptomatically, thus great scope exists for reducing late diagnosis by improving the testing practices of GPs.
