Reducing the length of time between HIV infection and diagnosis

In this week's BMJ, two analysis articles about testing for HIV argue for changes in policy that would expand the number of people routinely tested by promoting opt-out approaches.1 2 Both papers argue that this would increase the proportion of the population who know their serostatus and would decrease the number of late diagnoses of HIV. The papers agree about the benefits of swift diagnosis of HIV, including reduced mortality and morbidity, less onward transmission because treatment should reduce infectiousness, and reduced costs of acute treatment and lost productivity.

We argue that a more precise goal for any changes in policy should be to reduce the average time between HIV infection and diagnosis in people who become infected.3 This goal allows a range of measures of success beyond a CD4 count below 200×10⁶/l and acknowledges that the earlier HIV is diagnosed the better.

As the secretary general of the United Nations highlights, improved epidemiological outcomes are dependent on people being able to test in “a social and legal environment that is supportive and safe.”2 This needs to apply equally to people who receive a negative result as those who do not. Many of the benefits of having HIV diagnosed are not available to people without legal status in the United Kingdom because of the costs of drugs and continuing care. In addition to questions of access to treatment, a diagnosis of HIV has implications for sexual and social relationships, especially in the light of criminal prosecutions for the reckless transmission of HIV.4

HIV is one of the most stigmatised diseases.5 This stigma is embedded in pre-existing social inequality, and it is disappointing that neither analysis article takes account of the extent to which racism, xenophobia, and homophobia drive HIV related stigma. Huge increases in the number of people testing negative for HIV will not change those attitudes or the practices that maintain the social inequalities that reinforce HIV related stigma.

This call for expansion of routine opt-out HIV testing encompasses primary care and various acute settings.1 2 However, studies in the UK show that health professionals in non-HIV specialist settings discriminate against people with HIV.5 6 Opt-out testing policies would exacerbate this, and substantial investment in training and staff support would be needed to foster a “safe and supportive” environment as stipulated by the UN.

While calls for seroprevalence studies that are not linked to named individuals and a further examination of cost effectiveness are welcome,2 it is unclear what justification these could provide for expanded routine opt-out HIV testing. It is unlikely that the Centers for Disease Control (CDC) threshold for universal testing—when there is a 0.1% prevalence of HIV in a given population7—would be reached in many healthcare settings. While opt-out HIV testing in antenatal care is widely regarded as a success, it did not reach this threshold in England and Scotland in 2005.8 Moreover, a recent analysis of CDC guidelines suggests that counselling and testing that is targeted at populations most likely to have undiagnosed HIV would diagnose more HIV infections, prevent more HIV infections, and do this at a lower cost for each infection averted than would opt-out testing without specific consent or pre-test discussion.9

In the UK in 2005, 20 100 people were assumed to have undiagnosed HIV.8 Most were assumed to be men who have sex with men (9000), African born heterosexuals (5400), or people who inject drugs (500). Only 4900 were thought to be non-African born heterosexuals who do not inject drugs. With a relatively small number of undiagnosed people in the population—mainly in groups where access to healthcare services can be problematic—expanding HIV testing provision across a range of settings is unlikely to be cost effective. If such an expansion requires the omission of pre-test discussion, then this conflicts with UK national guidelines on HIV testing, especially for people at highest risk, who constitute three quarters of those with undiagnosed HIV.10 It also conflicts with evidence from a CDC sponsored randomised control trial that interactive client centred counselling during HIV testing could reduce subsequent risk behaviour and the incidence of sexually transmitted infections.11

Since the publication of the national strategy for sexual health and HIV,12 uptake of HIV testing by people attending UK genitourinary medicine clinics has increased yearly. In 2005, 80% of men who have sex with men were tested, compared with 61% in 2001, and 82% of heterosexuals were tested compared with 41%.8 While some people with undiagnosed HIV still attend these clinics without being tested, the proportion of UK residents with undiagnosed HIV has fallen yearly as the proportion of people who are tested for HIV at a sexual health clinic has risen.

Factors that influence the offer and uptake of HIV testing and whether patients return for the results include the sexual health clinic's policy on HIV testing (opt-in or opt-out)13 14 and how long people have to wait for results.15 Opt-out HIV testing is not a universal policy in genitourinary medicine clinics in the UK, even for African migrants and men who have sex with men. Moreover, waiting times for appointments and HIV test results vary and point of care (rapid) testing is relatively rare.

These data show that the possibilities for targeting and diagnosing people at highest risk of HIV have not been exhausted. Intensified targeting is challenging but is essential for a major impact on the time between infection and diagnosis. If this strategy proves effective we could then consider how to encourage HIV testing in people who are less likely to have HIV.