• HIV TESTING
• USERS PERSPECTIVE
• PUBLIC HEALTH

In April, it was reported in national news that licensed home HIV test kits were on sale in the UK for the first time.1 Of course, unlicensed (and potentially inaccurate)2 kits were available online more than 10 years ago, but a Spanish survey of >3000 men who have sex with men (MSM) conducted between 2010 and 2012 found that <10% knew that unauthorised tests were available online and <1% had used them.3 Home test kits have been available since 2013 in the USA; these are oral fluid tests, in contrast to the finger-stick blood test kit now on sale in the UK. A recent study found that a different finger-stick blood test for home use was more sensitive and specific than any of the four oral fluid kits tested.4 There are several arguments for and against home HIV testing, and this month's Clinical Round-up touches on the evidence that might support these arguments. In general, there is little research from the UK in this field: most studies are from sub-Saharan Africa, the USA, Brazil and other European countries.

The easiest argument to support in the ‘case for’ is that there is high public demand, or at least high levels of acceptability, for home HIV testing. This round-up is far from a systematic review, but in five recent surveys totalling >8000 HIV-negative MSM in Australia, France, Italy and the USA,5–9 >80% of survey respondents said they would consider buying a home test kit, and home testing was preferred to clinic-based testing, where these questions were asked. Non-white men (in the USA)7 and non-Anglo-Australian men (in Australia)5 had a greater interest in home HIV testing, as were some country-specific socio-economic groups. Convenience, speed and privacy were cited as the reasons for enthusiasm about self-testing in more than one study.5 ,6 ,8

Some may argue that home testing lacks immediate professional support for those testing positive, thus risking non-engagement with medical care, more difficult adjustment to the diagnosis and less effective partner notification. But it is equally possible that testing for HIV at home could be less stressful, more empowering, more convenient, better-supported and just a better experience for the person taking the test. Both possibilities will require evaluation in the UK and other countries where home kits are licensed.

One corollary of increasing use of home HIV testing is that shifting the task away from sexual health services and general practice may reduce workload. A potential cost is that opportunities for health promotion, STI testing and other services that a sexual health clinic provides may be lost, resulting in greater health needs in the long term. Again there are two sides to the argument, neither of which appears to have been addressed in research.

Another central argument for home HIV tests is that they will reach the untested fraction of seropositive people, recently estimated at 24% or 26 100 people in the UK.10 The counter-argument is that home test kits may be used mainly by the ‘worried well’, having almost no impact on the undiagnosed fraction or the rate of late HIV diagnoses. Therefore, health professionals have a responsibility—and an opportunity—to ensure that kits are targeted at the right people. If we monitor trends in diagnosed and undiagnosed HIV prevalence figures and see a spike in new HIV diagnoses in the UK over the next year or two, we may well have succeeded. In New York, an innovative pilot project supplied MSM with kits and invited them to test their partners before sex.11 After supplying only 27 men with kits, 100 contacts were tested and 6 new HIV diagnoses were made.

HIV testing is free on the National Health Service, but the cost of home test kits is currently £29.95.12 A feasibility study in Spain found that 40% of respondents would pay €20 for a test kit and only 18% would pay €30. Cost will quite likely be a disincentive to potential purchasers, reducing the population impact of the kits’ availability.13

A final concern is that real public health harms may arise. A mathematical model of widespread replacement of clinic-based testing by home HIV testing among MSM in Seattle predicted an increase in HIV prevalence. This was driven by the longer window period of home tests compared with laboratory tests, and by losses in the treatment cascade between diagnosis and linkage to care.14

There is no doubt that home HIV test kits are here to stay, despite uncertainties about the public health impact they will have. Among the UK's black African community, the Haus study is exploring some of these uncertainties,15 and other studies are planned in UK MSM. Meanwhile, kits will be bought, and used, and health services will need to respond to a rapidly moving target.