The impact of the transmission dynamics of the HIV/AIDS epidemic on sexual behaviour: A new hypothesis to explain recent increases in risk taking-behaviour among men who have sex with men
Introduction
Increases in some STI and related high-risk behaviours for STI and HIV/AIDS have been reported since the mid-nineties among men who have sex with men (MSM) in industrialised countries [1], [2], [3], [4], [5], [6]. Reasons for the increases in risk behaviours are not entirely clear but prevention fatigue, lack of awareness among younger MSM and treatment optimism because ART became widely available have often been put forward as possible explanations [3], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16]. However, most, if not all, of these reasons – including optimism toward the risk of developing AIDS among people living with HIV – have been identified in the early nineties and are therefore not unique to the ART era [17], [18], [19], [20], [21].
A recent meta-analytic review of 25 published studies on ART and sexual behaviour reported no significant overall effect between the use of ART or a reduced viral load and high-risk behaviours, but identified an overall positive association between positive beliefs about ART and high-risk behaviours [15]. The cross-sectional nature of the studies reviewed, however, makes it impossible to conclude on a causal relationship between optimism and high-risk behaviours. Optimism or beliefs may originate or intensify after someone engages in high-risk behaviours, acting as a posteriori self-justification [7]. Although some dimension of optimism was associated with high risk behaviour in cross sectional studies [15], other studies examining risk behaviours over time have shown that increases in risk are equally prevalent among the optimistic and the non-optimistic, thus questioning optimism as a driver of such change [9], [10]. In the only longitudinal study available to date [16], the only belief associated with an increase in unprotected sex, among HIV negative individuals was: ‘perceiving less HIV/AIDS threat’.
These conflicting results have led researchers to ask if the questions on optimism were properly formulated and to investigate if other reasons could explain the increase in high-risk taking behaviours following the wide scale availability of ART therapy [7], [9], [10], [12], [16]. The cornerstone of the present hypothesis is that the change in the dynamics of the HIV/AIDS epidemic before and after the introduction of ART has contributed to this change in high-risk taking behaviours.
Section snippets
Summary of the hypothesis: The number counts!
It is suggested that a decline in sexual risk activities has occurred at the population-level (cross-sectionally at the aggregate level) following the initial spread of the HIV/AIDS epidemic because AIDS mortality and severe morbidity disproportionately depleted the pool of high-risk taking individuals (i.e., individuals with several sexual partners or/and most likely to engage in unprotected sexual activities) [22], [23], [24], [25], [26]. As a result, non-volitional changes may have occurred
Volitional and non-volitional individual changes versus sexual environment changes
Potential changes in risk taking behaviours, as highlighted by mathematical modelling results [22], [23], are summarised and illustrated with simple social network diagrams.
According to mathematical modelling, changes in risk taking sexual behaviours occur at the population level, during the natural course of the HIV/AIDS epidemic, because AIDS related mortality or AIDS related illness (and cessation of sexual activity) disproportionately depletes the population of individuals with the riskiest
Theory of planned behaviour
Many social cognitive theories allow for extra-individual influences, even if such influences are infrequently assessed in interventions and even surveys. Although individually centred, the TPB is useful to our current work because it offers the possibility to assess extra-individual influences at several levels. The theory of planned behaviour (TPB, see Fig. 2(a)) is the dominant model for predicting and understanding health-related intentions and behaviour (see Armitage and Conner [35]; Godin
Discussion
We argue that “sexual partner availability” is an important determinant of sexual behaviour. According to this hypothesis changes in sexual partner availability caused by the HIV/AIDS epidemic and the wide scale use of ART could partly explain changes in sexual behaviour in the early eighties and mid-nineties among MSM both at the population-level and individual level. Indeed, mechanisms that affect availability such as the use of the internet to find sexual partners, has been associated with
Acknowledgements
M.C.B. thanks MRC for financial support and F.I.B thanks FIOCRUZ PAPES grant 250.250.122.
References (60)
Modelling the effects of AIDS on gonorrhea epidemiology
Math Comput Modell
(1992)The theory of planned behavior
Organ Behav Hum Dec
(1991)- et al.
Theoretical approaches to the promotion of physical activity: forging a transdisciplinary paradigm
Am J Prev Med
(2002) - CDC. Increase in unsafe sex and rectal gonorrhea among men who have sex with men-San Francisco, California, 1994–1997....
- et al.
Gonorrhea in the HIV era: a reversal in trends among men who have sex with men
Am J Public Health
(2001) - et al.
The gay ’90s: a review of research in the 1990s on sexual behavior and HIV risk among men who have sex with men
AIDS
(2000) - et al.
Trends in sexual behaviour among London homosexual men1998–2003: implications for HIV prevention and sexual health promotion
Sex Transm Infect
(2004) - et al.
Risk behaviour and sexually transmitted diseases are on the rise in gay men but what is happening with HIV
Curr Opin Infect Dis
(2002) - et al.
A summary report from Amsterdam: increase in sexually transmitted diseases and risky sexual behaviour among homosexual men in relation to the introduction of new anti-HIV drugs
Euro Surveil
(2002) - et al.
HIV treatments optimism is associated with unprotected anal intercourse with regular and with casual partners among Australian gay and homosexually active men
Int J STD AIDS
(2002)
High risk sexual behaviour increases among London gay men between 1998 and 2001: what is the role of HIV Optimism?
AIDS
Men who have met sex partners via the Internet: prevalence, predictors, and implications for HIV prevention
Arch Sex Behav
Increasing realism among gay men in Sydney about HIV treatments: changes in attitude over time
Intl J STD AIDS
Sexual behavior changes and protease inhibitor therapy
SEROCO Study Group AIDS
Influence of a partner’s HIV serostatus, use of highly active antiretroviral therapy, and viral load on perceptions of sexual risk behavior in a community sample of men who have sex with men
J Acquir Immune Defic Syndr
Combination therapies for HIV and sexual risk behavior among gay men
J Acquir Immune Defic Syndr
Highly active antiretroviral therapy and sexual risk behavior: a meta-analytic review
JAMA
Perceived viral load, but not actual HIV-1-RNA load, is associated with sexual risk behaviour among HIV-infected homosexual men
AIDS
Declining gonorrhoea rates in The Netherlands, 1976–1988: consequences for the AIDS epidemic
Genitourin Med
Prevalence of antibodies to human immunodeficiency virus, gonorrhoea rates, and changed sexual behaviour in homosexual men in London
Lancet
Gonorrhoea as an indicator of altered sexual behaviour and as a surrogate marker of HIV concern: a 13-year analysis in Newcastle
Int J STD AIDS
Trends in sexual behaviour in a cohort of homosexual men: a 7 year prospective study
Int J STD AIDS
Optimism, coping, psychological distress, and high-risk sexual behavior among men at risk for acquired immunodeficiency syndrome (AIDS)
J Pers Soc Psychol
Changes in the transmission dynamics of the HIV epidemic after the wide-scale use of antiretroviral therapy could explain increases in sexually transmitted infections: results from mathematical models
Sex Transm Dis
AIDS mortality may have contributed to the decline in syphilis rates in the United-States in the 1990s
Sex Transm Dis
Effect of differential mortality on risk behaviour change in cohort studies
J Acquir Immune Defic Syndr
Belief, attitude, intention, and behavior: an introduction to theory and research
Sexual risk behaviour relates to the virological and immunological improvements during highly active antiretroviral therapy in HIV-1 infection
AIDS
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