Current UK policy on HIV testing has been established as a result of a number of factors:

• Desire to avoid compulsory testing.
• Desire to avoid discrimination and stigmatisation.
• Qualified medical support for widespread testing.
• Lack of support from the voluntary sector for widespread testing.

Debates about HIV testing have tended to focus on the complex decision–making process which faces individuals who are considering whether or not to test. Many doctors and voluntary organisations continue to argue that HIV testing is an individual decision. The outcome of such a consensus is that the wider social consequences of not promoting HIV testing are never discussed because this would be seen to undermine individual choice.

However, it is important to discuss the negative consequences of not promoting HIV testing more aggressively. These include:

• Avoidable morbidity and mortality.
• Avoidable mother-to-baby transmission.
• Frequent incorrect assumptions about HIV status in sexual relationships.
• Underestimates of the size of the infected population and of the costs of the AIDS epidemic.

Avoidable mortality and morbidity

A study of people with HIV diagnosed with AIDS between 1989 and 1992 found that only 51% were aware of their HIV status more than nine months prior to an AIDS diagnosis. Researchers considered this time interval significant because people aware of their HIV status more than nine months before an AIDS diagnosis were less likely to benefit from antiretroviral therapy and prophylactic treatment which delayed disease progression, researchers argued.

Rates of testing varied substantially amongst different risk groups. Injecting drug users attending drugs dependency units were most likely to have had their HIV infection diagnosed, whilst heterosexual men and women were least likely to have been diagnosed.

There has been a marked fall in the number of new AIDS diagnoses amongst people who have been aware of their HIV status for some time, suggesting that anti–HIV therapy is having an impact on disease progression. An increasing proportion of new AIDS diagnoses are occurring in people who had never been tested or had only been diagnosed with HIV less than three months before the onset of an AIDS–related illness. For them, their HIV diagnosis probably comes too late for anti–HIV therapy to delay the onset of AIDS.

In the UK, AIDS diagnoses fell by 25% during 1997, although there were substantial regional variations. This followed a 15% increase in AIDS diagnoses in 1996.

In inner-London hospitals, new AIDS diagnoses fell by 31% in 1997, but outer-London hospitals diagnosed exactly the same number of people with AIDS in 1997 as they did in 1996 – 121 cases.

Although there is no evidence that Africans in the UK have a shorter life expectancy once they have been diagnosed with AIDS (compared with other groups of people with AIDS), the rate of new AIDS diagnoses amongst African people has hardly fallen at all. Every year Africans diagnosed with AIDS form a larger proportion of UK AIDS cases, and whilst new AIDS diagnoses fell 35% amongst gay men in 1997, they fell by only 6% amongst Africans.

This difference probably explains why the decline in new AIDS diagnoses was much more pronounced in hospitals north of the Thames compared with those south of the river – a 32.5% fall in the North Thames region compared with only a 2.4% fall in the South Thames region as a whole. In Brighton – part of the South Thames district but with a HIV–positive population that consists almost entirely of gay men – AIDS cases between 1996 and 1997 fell by 23%.

Diagnosed too late?

Among gay men, their average CD4 count when they first test HIV–positive has remained almost constant since 1990, at around 300 to 350.

British guidelines currently (June 2003) recommend that anti–HIV therapy should ideally begin before the CD4 count falls below 200, regardless of viral load.

Amongst Africans in the UK, fewer than 25% know their HIV status at least two months before developing an AIDS–defining illness, according to data collected by the CDSC. Even amongst gay men, fewer than 50% know their HIV status at least two months before they develop AIDS. The CDSC note that the number of new HIV diagnoses amongst gay men fell in 1997 “despite the existence of a well publicised, effective treatment regimen which was expected to lead to an increase in testing in members of this risk group”. In total, more than 450 people were diagnosed with AIDS in 1998 without prior knowledge of their HIV status, or less than two months after learning it.

A whole issue of the British Medical Journal in 1998 was devoted to the important issue of antenatal testing, with a warning that current British policy was resulting in dozens of avoidable infections amongst new–born children. In contrast, the issue of identifying the thousands of HIV infections amongst untested gay men and Africans in the UK has still failed to excite a much–needed debate.

No further data have been produced on this question since 1993, so it is impossible to tell whether trends in HIV testing have changed amongst gay men or African communities. However, given the benefits of current treatment regimens it is all the more worrying that a large proportion of HIV–infections appear not to be identified until a relatively advanced stage of the disease.

Avoidable mother-to-baby transmission

The success of AZT treatment during pregnancy and labour (see HIV transmission: mother to baby transmission) has highlighted the need to identify HIV–positive mothers prior to delivery in order to offer AZT and other antiretrovirals. Countries with aggressive policies of maternal HIV testing, such as France and some US states, have witnessed dramatic falls in mother-to-baby transmission since the beginning of 1995. In the UK, by contrast, the Department of Health waited until August 1999 to announce that all pregnant women in England would be offered, and advised to take up, an HIV test during pregnancy, regardless of the HIV prevalence of the region in which the woman lived.

However, vertical transmission rates among women in the British Isles were dramatically reduced during the 1990s, according to a report published in the British Medical Journal at the end of 1999. Data on 800 non-breastfed children born to diagnosed HIV-positive mothers, up until January 1999, showed that the vertical transmission rate fell from 19.6% in 1993 to 2.2% in 1998. 

See HIV testing, pregnancy and children for further discussion of this issue.

Frequent incorrect assumptions about HIV status in sexual relationships

Ford Hickson of SIGMA Research has highlighted the role which incorrect assumptions about HIV status play in facilitating unprotected sex. It has also been noted that untested men tend to have the highest rates of unprotected sex with regular partners in the UK, and that HIV–positive gay men tend to have less unprotected sex with casual partners (Coxon). The extent to which incorrect assumptions about HIV status contribute to new infections in unclear, but it is probably reasonable to assume that such assumptions are widespread.

This issue is discussed in more detail in Negotiated safety below.

Underestimates of the size of the infected population and the costs of the epidemic

Although researchers have been able to produce reasonably accurate estimates of levels of HIV infection in the population, it is much more difficult to determine rates of new infections, as recent controversy over new infections amongst gay men shows. The encouragement of regular testing amongst those at highest risk might help to give a clear picture of how and why people are becoming infected, and help us to design better prevention efforts. It would also make the potential future costs of treatment easier to project, if not to finance.