The first thing that needs to be stated in any chapter on HIV prevention is that it can work.

HIV has become a pandemic because it has a lethal combination of properties:

• transmission via that most taboo, intractable and instinctive of human activities, sex.
• a long asymptomatic incubation period during which people are healthy, sexually active - and infectious.

Changing sexual behaviour involves revolutionising cultural attitudes, confronting taboos, reaching out to the most marginalised and despised populations and including them in dialogue, and helping people make rational decisions about their health at the very moments when they are least rational.

It is tempting to conclude at times that only biomedical interventions such as treatment and vaccines can ever have an effect on HIV. But the largest meta-review of HIV prevention activities ever conducted (Johnson 2002) found that the overall effect of group- and community-level behavioural interventions targeted at gay men was a reduction in HIV incidence of 26 per cent.

This may not sound like a great reduction. But no public health intervention is ever 100 per cent successful. In addition public health measures may take decades to have an effect. For instance, in the USA, the proportion of driving deaths caused by drunk drivers declined from 57 per cent in 1982 to 45 per cent in 1992. This 10 per cent reduction was considered a major victory for public awareness campaigning and legal changes.

One paper (Stryker 1995) put it this way: “Given experience in other health behaviour change endeavours, non-interventions are likely to reduce the incidence of HIV infection to zero; indeed, insisting on too high a standard for HIV risk-reduction programs may actually undermine their effectiveness.”

However small reductions in HIV incidence timed correctly may make a great deal of difference.

To take an example, the first generation of topical microbicides are unlikely to prevent more than 50 to 60 per cent of HIV infections when used. But, according to The Global Campaign for Microbicides, (2005) “Researchers have developed a mathematical model that shows that if even a small proportion of women in lower income countries used a 60 per cent efficacious microbicide in half the sexual encounters where condoms were not used, 2.5 million HIV infections could be averted over 3 years”.

The 26 per cent reduction typical of prevention interventions is of course an average, and includes many interventions that did not work. Specific interventions can work much more dramatically. To three of the two most widely-quoted examples:

• In Uganda, a countrywide programme of AIDS awareness-raising initiated by the Ugandan president in 1986 led to demonstrable reductions in risky behaviour and at least contributed to a two- to fourfold reduction in HIV prevalence.
• In Thailand, a single-minded campaign to institute 100 per cent condom use in commercial sex establishments brought down the HIV incidence in young men from 2.5 per cent in 1991 to 0.5 per cent in 1993.
• The UK has its own major triumph. In 1986 HIV prevalence among injecting drug users in Edinburgh was approaching 50 per cent. Reversing a police policy of confiscating needles and instituting needle exchange forced annual HIV incidence down to two per cent. Just seven per cent of Britons with HIV have caught it from needle-sharing, as opposed to 28 per cent in the USA and 80 per cent in Russia.

HIV prevention can include a myriad of activities, but falls into five broad classes:

• Biomedical approaches include HIV treatment, because antiretrovirals reduce people’s infectiousness (a study in San Francisco calculated that the average viral load, and therefore infectiousness, of gay men in the city had been cut by two-thirds since HAART). Post-exposure prophylaxis - taking HIV drugs immediately after a risky exposure to prevent HIV – is another intervention. Needle exchange is another. Barrier methods like condoms are biomedical, though programmes to ensure their use are not, and the same will apply to developing prevention technologies such as microbicides.
• Individual approaches include one-to-one counselling (including voluntary counselling and testing), cognitive behavioural therapy, face-to-face detached or outreach work, telephone helplines and certain internet interventions.
• Group approaches are those delivered to small groups of individuals, often from the same peer group, and are usually facilitated in some way. They include school sex education and small-group work that usually includes both information and risk reduction skills training.
• Community interventions are delivered to the whole population or (more frequently) a target audience; the difference from the previous interventions being that individuals do not need to seek out the programme. They include media stories and small-media resources (e.g. leaflets and posters), condom distribution schemes, the empowerment and development of communities (including communities of people with HIV), and some internet interventions like chat rooms.
• Sociopolitical interventions include legal change such as the decriminalisation of homosexuality or intravenous drug use; legal sanctions such as the criminalisation of transmission; and policy interventions which may permit other types of prevention work, such as allowing needle-exchange.

Given, then that (for instance) a combination of reduction programmes and HAART should have reduced HIV incidence in gay men in the developed world, why, in many cases, has it not?

Although it is important that a country’s HIV prevention ‘package’ includes as wide a variety of interventions as possible (because what is appropriate to a heterosexual virgin teenager is not appropriate to a gay male sex worker), it’s also important to be aware that HIV interventions are not necessarily synergistic, (reinforce each others’ effects). On the contrary, they may be antagonistic.

To take some examples:

• The advent of HAART has reduced fear of death among the community at large and gay men in particular, and has also increased the population of healthy, sexually active people with HIV. Between them, these contribute to cancelling out the net drop in infectiousness in the community.
• Opponents of condom distribution programmes say that providing condoms only encourages sexual activity.
• Doctors fear that providing post-exposure prophylaxis will lead to greater risks being taken.
• Some studies of peer-led and facilitated group interventions have found that their effectiveness is compromised by the ‘shame factor’ – participants being reluctant to discuss times when they have deviated from the group norm of sexual behaviour.

In addition, the target audience dictates the message, and HIV prevention interventions devised for gay men in the pre-treatment era are no longer appropriate for a large proportion of the world’s vulnerable population.

It is interesting to speculate how HIV prevention would have developed in the world’s richer countries if the group most affected from the start had been young heterosexual women, as in Africa and other parts of the developing world, instead of gay men.

• Would an HIV prevention strategy based on an essentially male-controlled device – the condom – have been the primary focus of prevention?
• Would strategies encouraging sexual abstinence or monogamy have been more prominent?
• Would the invoking of criminal sanctions against infection have happened earlier?
• And would a general presumption of ‘shared responsibility’ in sexual relationships and negotiation have been tempered much earlier by questions of power and inequalities of gender, age and income?

Because of the complex synergies and antagonisms possible between interventions, in the last decade HIV prevention, at least in the UK and the developed world, has been utterly transformed from what was essentially the social marketing of a simple message – ‘Choose Safer Sex’ – into a complex, contradictory and extremely politicised set of dialogues featuring heated debates between proponents of:

• abstinence versus comprehensive sex education.
• the promotion of condoms versus the promotion of monogamy.
• harm reduction versus risk elimination.
• ‘normalising’ disclosure and HIV testing versus confidentiality and patient rights.
• and whether HIV-negative or HIV-positive people are the best targets for – and the best originators of - prevention messages.

As well as becoming more complex, as an endeavour HIV prevention has also become by many to be seen as less effective.

HIV infection continues to climb in much of the developing world, and certain countries like India and Russia are widely forecast to be at the ‘tipping point’ for the development of generalised epidemics. Although prevalence has fallen in some African countries that have been the focus for intensive prevention efforts, there are fears that the cost of providing global access to antiretrovirals may impact adversely on community prevention initiatives. According to UNAIDS by July 2005 only one in five people needing HIV prevention had access to prevention programmes and only one in ten people had been tested for HIV.

These fears are best exemplified by the 2002 paper (Marseille 2002) in The Lancet by Elliot Marseille and colleagues, who argued that HIV prevention is 28 times more cost-effective than providing treatment in the developing world, and that “funding HAART at the expense of prevention means greater loss of life.”

Although Marseille’s views were criticised as placing a false opposition between prevention and treatment, concerns continue to be expressed that over-emphasising treatment at the expense of prevention in not cost-effective.

There is also concern that treatment without proper education will lead to increased transmission of drug-resistant HIV in the developing world, with a resultant rapid loss of sustainability of cheap antiretroviral regimens.

However these arguments ignore the fact that providing antiretroviral drugs provides hope, which is in turn a major generator of positive prevention behaviours such as increased testing, increased disclosure of HIV status, reduction of stigma, and an examination of community sexual norms. In one district in Uganda, for instance, the arrival of antiretrovirals in the area led to a 23-fold increase in the number of people coming forward for testing.

In the developed world, HIV prevention work faces an uphill battle both against the loss of funding due to the cost of HAART and changes in behaviour leading to a greatly increased incidence of sexually transmitted diseases, especially among gay men, and, in some cases, HIV.

The USA has started to see an increasing degree of inequality when it comes to HIV vulnerability between ethnic minority and particularly African-American people and the white majority. A recent survey of gay men (Centers for Disease Control, 24 June 2005), for instance, found that HIV prevalence among Afro-American men who have sex with men it was more than twice what it was in whites; among Afro-Americans in general it is four times that of the general population: and four out of five women diagnosed with HIV (Centers for Disease Control, 16 June 2005) is black or Hispanic.

There has been a loss of certainty about how to do effective HIV prevention work with poor black women and men who, while having sex with men, may not identify as gay. With gay men in general there have been concerns that two decades of prevention success could be wiped away by recreational drug use.

Gay prevention campaigners are concerned that the global emphasis on HIV is obscuring the fact that men who have sex with men are still the most vulnerable population for infection in most developed countries. For instance, 80 per cent of the people who acquired their HIV in the UK last year were gay men, and sexually active gay men, who form no more than one in 40 of the UK population, are at least 200 times more likely to catch HIV in the UK than heterosexuals (Health Protection Agency, 2005).

While European countries have not seen the same development of HIV health inequality as the USA, increasing HIV prevalence among immigrant populations who may have limited access to HIV treatment and to prevention messages has led to fears of a ‘second generation’ epidemic among minorities, though there are few signs so far that this is materialising.

This widely-held feeling that HIV prevention has lost its way and that we no longer live in a simple ‘safer sex’ world has led to an increased focus on the development and testing of new prevention technologies such as pre-exposure prophylaxis and microbicides.

The changes in HIV prevention work have been predicated upon two huge historical changes.

The 'feminisation' of AIDS

This has transformed HIV educators’ views of the position of the HIV-negative partner in sex. Almost all countries have seen increased numbers of women diagnosed with HIV, to the extent of women now forming the majority of people affected in sub-Saharan Africa. The fact that for many of these women – a lot of whom are wives - it is quite simply culturally and personally impossible to negotiate condom use with male partners has led on the one hand to the drive to develop microbicides and other female-controlled technologies, and on the other for proponents of abstinence and monogamy to say that these are the only strategies that protect vulnerable women against male sexual dominance.

Post-HAART optimism

Although studies (Stolte 2004; Huebner 2004) have produced contradictory results as to whether ‘treatment optimism’ is responsible for the observed decreased condom use and increased levels of STIs, especially among gay men, it makes intuitive sense that when the extreme threat of a universally fatal disease that has killed lovers and friends is lifted, some people in vulnerable communities who might previously have maintained safer sex become prepared to take risks. The increased numbers and improved state of health of HIV-positive people has also meant that more continue to be sexually active. This has led to a new and anxious concentration on people with HIV as sexual beings and vectors of disease.

In this chapter, we will therefore look at HIV prevention as a much broader set of techniques and messages than just ‘choose safer sex’. To bring some order to a complex field we will use the template of the African ‘A-B-C’ prevention model, with a couple of additions, without implying that this is an endorsement of it as the HIV prevention approach.

A is for Abstinence will look at whether there is evidence that programmes which encourage sexual abstinence or delay sexual debut in young people help to reduce HIV infection.

B is for Being faithful and Behaviour change will look at the degree to which HIV prevention projects have changed sexual behaviour in general, especially in adults.

C is for Condoms and other barrier methods will look at the evidence for the effectiveness of male and female condoms in preventing HIV and other STIs and will review recent evidence on the effectiveness of programmes to encourage condom use.

D is for disclosure, negotiated safety and serosorting Will look at measures people with and without HIV take to reduce risk as an alternative to, or in addition to, using condoms

E is for Emergent technologies Will review available and potential new prevention technologies.

References

Centers for Disease Control. A Glance at the HIV/AIDS Epidemic. Centers for Disease Control. See http://www.cdc.gov/hiv/dhap.htm 16 June 2005.

Centers for Disease Control. HIV Prevalence, Unrecognized Infection, and HIV Testing Among Men Who Have Sex with Men - Five U.S. Cities, June 2004-April 2005. CDC Mortality and Morbidity Weekly Report. See http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5424a2.htm 24 June 2005.

Elford, J et al. Peer education has no significant impact on HIV risk behaviours among gay men in London. AIDS 15(4): 535-538. 2001.

Global Campaign for Microbicides Factsheet: Frequently Asked Questions about Microbicides. See http://www.global-campaign.org/clientfiles/FS2-FAQs-May05.pdf Revised May 2005.

Health Protection Agency Quarterly HIV/AIDS Surveillance tables. See http://www.hpa.org.uk/infections/topics_az/hiv_and_sti/hiv/epidemiology/files/quarterly.pdf June 2005.

Huebner D et al. A longitudinal study of the association between treatment optimism and sexual risk-behaviour in young adult men who have sex with men. 15^th International AIDS Conference, Bangkok, abstract D11585, 2004.

Johnson W et al. HIV prevention research for MSM: a systematic review and meta-analysis. JAIDS 30 (suppl. 1), S118-129. 2002.

Marseille E, Hofmann PB, Kahn JG. HIV prevention before HAART in sub-Saharan Africa.The Lancet 359(9320), 1851-1856, 2002.

Stolte I et al. Homosexual men change to risky sex when perceiving less threat of HIV/AIDS since availability of highly active antiretroviral therapy: a longitudinal study. AIDS 18: 303-309, 2004.

Stryker J et al. Prevention of HIV infection. Looking back, looking ahead. JAMA 273(14), 1995.