The need for a non-judgmental harm reduction approach to the prevention of sexual transmission of HIV
"Prevention fatigue" is said to pose a threat to the acceleration and sustainability of HIV prevention efforts. However, the prevention discourse is often pitched in "all or nothing" terms, while the concept of progressive risk reduction has not been sufficiently applied. Renewing the discourse on safer sex and adopting approaches that are tailored to the needs of individuals and communities might help to boost flagging programmes.
"Prevention fatigue" has been raised as an issue for the gay community in most industrialised countries [
11]. In France, repeated cross-sectional studies carried out among readers of the gay press have documented increases in the rate of unprotected anal intercourse, from 20% in the nineties to 33% in 2007 [
12]. Similar relapses in risk behaviour have been observed in other countries [
13,
14]. The gay community has been widely criticized for insufficient action and continued high levels of unsafe sex. However, a national survey of sexual behaviour carried out in France between October 2005 and March 2006 among more than 12,000 individuals, shows that men who have sex with men (MSM) have more condom use experience than heterosexual populations [
15]. In this study, the proportion of people who reported condom use in the last year is higher among MSM than among men who have sex with women (MSW), especially in stable relationships (93% of MSM vs. 81% of MSW with three partners or more in the previous year used condoms, and 53% of MSM vs. 17% of MSW with one partner only in the last year used condoms). This suggests that MSM may achieve equal or higher comfort levels with condoms than heterosexual populations.
Instead of dwelling on the times when so many members of the gay community died from AIDS related illnesses, despite widespread community action and considerable changes in sexual behaviour, it would be more constructive to work at reaching out to, and developing pragmatic solutions for those who, for one reason or another, do not consistently practice safe sex.
Understanding the conditions of risk and how people interpret risk is of key importance when designing appropriate HIV prevention strategies [
16,
17]. For many people, HIV risk forms part of the fabric of their life. Take the woman who is afraid to ask her husband to use a condom because he might beat her, the young gay man who is learning to enjoy his sexuality and struggling to manage new sexual relationships, or the sex worker who has to deal with clients who refuse to use condoms. These are real life situations in which systematic condom use is just not happening. The issue is how to manage risk in ways that minimize the impact of risky exposures. This is challenging in a society that refuses to accept that people take risks and blames those who do.
A way forward is to adopt a non-judgmental harm reduction approach to the prevention of sexual transmission of HIV. HIV prevention programmes should be designed under the assumption that, with few exceptions, HIV-negative people do not want to get the virus; and that PLWHA do not want to transmit the virus. Our work on the ground shows that one of the greatest concerns of PLWHA is ongoing HIV transmission [
18].
People do care. Those who take risks also care. Despite the lack of evidence on the effectiveness of this approach, some women use other barrier methods, such as diaphragms, when they cannot use male or female condoms, in the hope of reducing their risk of HIV infection, because these methods are under their control and undetectable by their sexual partner [
19].
Among HIV-positive MSM, serosorting is frequently observed [
14]. Although it is not demonstrated to be effective for protecting HIV-negative individuals, some individuals already living with HIV are choosing this approach with the goal of unprotected intercourse. MSM have also been observed to adapt their sexual practices through strategic positioning [
20]. Among networks of gay men who otherwise seek unprotected intercourse, condoms may be used in the event of sexually transmitted infections [
21]. Of course, the effectiveness of these strategies in reducing HIV risk is uncertain. The point is that people who have difficulties with condom use do care at some level about HIV risk, or else they would not bother to use alternative strategies to reduce this risk.
There is some urgency to move beyond the "all or nothing" approach to preventing sexual transmission of HIV – as we have for the prevention of transmission of HIV through drug use- and renew the discourse about safer sex. Partner reduction and condom use already represent harm reduction approaches to dealing with risky sexual behaviours. Further multidisciplinary research is required to assess additional risk reduction strategies, including those observed on the ground.
The control of HIV viral load: a new approach to sexual risk reduction?
The reduction of maternal viral load is the mainstay of efforts to prevent perinatal HIV transmission [
22]. Viral load suppression has also been proposed as a strategy to reduce sexual transmission, in recognition of the strong association between viral load and risk of transmission. Early studies conducted in Rakai, Tanzania, among serodiscordant heterosexual couples before the antiretroviral era indicated that the HIV transmission rate is almost linearly associated with viral RNA levels in the plasma [
23]. The advent of antiretroviral treatment (ART) spurred efforts to determine the impact of viral load suppression on HIV transmission.
Cohorts of sero-discordant couples have been observed throughout the ART era, and although the results are still sparse, they show that ART-induced viral load suppression is associated with reduced levels of HIV transmission [
24]. In a Spanish cohort of serodiscordant couples, HIV transmission was reduced by 80% after introduction of higly active ART (HAART). In this study, transmission never occurred when virological suppression was achieved in the positive partner [
25].
At the end of 2007, a statement issued by Swiss experts became the subject of much controversy [
26]. Based on a review of Vernazza [
27], the authors concluded that condom use may not be necessary in stable heterosexual serodiscordant couples in which virological suppression had been achieved in the positive partner for at least six months. Many concerns have been raised about this position. It has been pointed out that virological suppression in the blood is not necessarily associated with suppression in the genital fluids [
28]. In addition, the data refer to stable heterosexual couples with no intercurrent sexually transmitted infection, which might lead to peaks in viral load. Despite these limitations, the results of the Swiss study may hold promise for sero-discordant couples, the population in which much transmission occurs in high prevalence countries [
29]. It is not, however, clear how these results might apply to other populations at risk of HIV. ART may therefore be retained as a useful additional risk reduction strategy at the individual level, but more research is needed to determine its contribution to "combination prevention" within public health programmes.
The Swiss controversy gives prominence to the uneasy question of "when to start ART". The prospects of treating HIV-positive people for public health purposes, and not only to achieve benefits at an individual level, raises many complex issues. It is still an open question whether increasing the 200 CD4 threshold point globally recommended for initiating ART to the level recommended in most industrialized countries [
30] would have an impact on HIV incidence. Recent modeling results provide a compelling argument that increasing ART use could lead to a dramatic reduction of HIV incidence, even when considering an increase in risky behavior [
31]. This remains a priority area for further research.
The need for comprehensive services for PLWHA, including positive prevention
These data on the role of viral load on HIV transmission and behaviour change among PLWHA suggest that untreated PLWHA are more likely to transmit the virus, and underline the urgent need to reach this population with comprehensive prevention, care and support services. In all settings, PLWHA, while in good health, are of limited interest to health care workers, as they are not eligible for treatment, and, as a result, they tend to receive only limited psychosocial support services, if any at all. These services are critical to support safer sex practices. Treatment adherence support programmes have already been introduced in several settings and have been shown to be effective in promoting adherence when they are focused not only on treatment but also on the person and on all aspects of daily life [
35].
For instance, Spire and others recently reported the results of a comprehensive programme for PLWHA in Phnom-Penh that was highly effective on treatment adherence. 95% of participants were fully adherent after two years of treatment [
36]. Similar approaches could be helpful in designing behavioural interventions for individuals living with HIV, but not yet requiring treatment, which would empower them to adopt and maintain safer behaviours.
For PLWHA under treatment, all interventions that maintain long-term virological success are likely to reduce HIV transmission risk. However, to achieve this, a comprehensive approach that integrates all essential prevention, care and support services is required, to make the most of potential synergies. Several results obtained through multidisciplinary studies in France and Italy suggest that perception of treatment toxicity is a significant factor influencing adherence [
37‐
39] as well as sexual risk behaviour [
40,
41]. The more side-effects PLWHA experience, the less adherent they are, and the less likely they are to use condoms systematically. This in turn negatively influences their quality of life [
42]. Taking into account the patient's reported clinical outcomes could help when designing the best strategies to reduce viral load and risk behaviours.
This positive relationship between perception of health and consistent condom use has been confirmed in other studies, conducted among a cohort of PLWHA infected through drug use in France [
43] and among PLWHA enrolled in the Agence nationale de recherches sur le sida et les hépatites virales (ANRS) Trivacan trial in Côte d'Ivoire [
44]. In these two distinct populations, the same relationship between the capacity to consistently use condoms and the lack of perceived side-effects associated with ART was observed.