The range of settings in which people test for HIV has expanded significantly in recent years in England, according to a new Public Health England report on HIV testing services. It includes new estimates of the numbers of people who test and re-test for HIV, suggesting that relatively few people at elevated risk of HIV take a test as often as recommended.
While most new HIV diagnoses continue to be made in sexual health clinics, significant numbers are made in a wide range of other settings:
- Sexual health services (75.4% of male diagnoses and 65.9% of female diagnoses)
- Hospital wards / in-patient services (6.6% male, 8.8% female)
- General practices (5.9% male, 7.3% female)
- Hospital out-patient services (4.1% male, 6.0% female)
- Antenatal clinics (5.4% female)
- Community settings (2.5% male, 1.9% female)
- Other (5.5% male, 4.7% female).
How many people need to be tested to diagnose one person with HIV?
The report compares the effectiveness of different testing services in reaching people with previously undiagnosed HIV. This is another way of looking at the positivity rate of each type of service.
By this measure, self-sampling is one of the most effective services (139 people tested for one reactive result), compared to hospitals and other secondary care services (175 people tested for one diagnosis), community settings (181 people), GPs in high-prevalence areas (217 people) and GPs in extremely high-prevalence areas (228 people).
Overall, sexual health services have a lower positivity rate (442 people tested for one diagnosis). But the figures are much higher in priority populations testing in sexual health services, including gay men (80 men tested for one diagnosis), gay men who’ve recently had a sexually transmitted infection (36 men), people born in high-prevalence countries (127 people) and people of black African ethnicity (145 people). Among people testing in sexual health clinics because they had been told that they had a sexual partner with HIV (partner notification), just 26 needed to be tested for one diagnosis.
When people not belonging to any of the priority groups test in sexual health services, 1333 people need to be tested for one diagnosis. The number of people in the general population is huge while the proportion who have HIV is small. Nonetheless, 29% of all diagnoses made in sexual health services are in people who are not gay men, black African, or born in a high-prevalence country – and late diagnoses frequently occur in people not belonging to obvious risk groups – showing the importance of maintaining HIV testing provision for the wider population.
While self-testing, self-sampling and community testing projects may have high positivity rates, the relatively small scale of these activities means that their overall impact on HIV diagnoses is low. Just over 22,000 people were tested by self-sampling, just over 20,000 through community testing, and just under 27,000 self-testing kits were obtained during 2016. (In contrast, over a million people tested in sexual health services.)
No sign that testing recommendations are being followed by gay men at higher risk of HIV infection
Gay and bisexual men are advised to test for HIV at least once a year – and every three months if they are at higher risk of acquiring HIV. Moreover, men and women of black African ethnicity are advised to have regular tests if having sex without a condom with new or casual partners.
Public Health England’s data suggest that only a minority of people test so frequently, although it should be noted that due to confidentiality protections, individuals cannot be tracked across different sexual health clinics. The clinics know if the same person tests more than once in their clinic during a year, but do not know about tests done at other sexual health clinics, at GPs or elsewhere.
Only 28% of gay men who tested at sexual health clinics had already tested once at the same clinic in the previous year and only 8% had tested at least twice at the same clinic in the previous year. Nonetheless, the figures are better for men with sexually transmitted infections (43%) and overall, the numbers of gay men re-testing within a year have increased by 57% since 2013.
Moreover, 13% of African men or women re-tested at the same clinic within a year.
The report also includes calculations of testing coverage, using estimates of the total populations of gay and bisexual men and of black African men and women. This includes tests done in sexual health services, community settings or self-sampling. It does not include tests carried out in other hospital services, at GP practices or elsewhere.
Just under 126,000 tests were conducted in the approximately 582,000 gay and bisexual men living in England – in other words, just 22% of men tested in the settings that were surveyed. There is substantial regional variation with more men living in London testing (32%) than elsewhere.
There were around 54,000 tests done in the 960,000 African men and women living in England – only 6% of African men and women. The proportion tested was much higher in the West Midlands (23%) and London (13%) than in many other regions (3% or under in the South West, South East, North East, North West and East Midlands).
Public Health England’s data also show an increase in the number of people attending sexual health services who turn down the offer of an HIV test. This has been seen in women born in high prevalence countries (refusals up 56% since 2012), black African women (up 52% since 2012) and people who are not gay men, black African, or born in a high-prevalence country (up 27%).
Public Health England. HIV Testing in England: 2017 report.