Methamphetamine users who identify as heterosexual double risk of sexual activity: more likely to have casual sex and multiple partners

March 2018
McKetin R, Lubman DI, Baker A, Dawe S, Ross J, Mattick RP, Degenhardt L. (2018). The relationship between methamphetamine use and heterosexual behaviour: Evidence from a prospective longitudinal study. Addiction. doi: 10.1111/add.14181

Methamphetamine is now a global public health concern, being consumed by an estimated 14-53 million people world-wide in 2015. A potential implication of methamphetamine use is for the transmission of HIV and other sexually transmitted infections (STIs).

The authors, a collaboration between the National Drug Research Institute and the National Drug and Alcohol Research Centre, Turning Point, the University of Newcastle and Griffith University, used data from the MATES cohort, 319 methamphetamine users in treatment, to examine the relationship between methamphetamine use and sexual activity.

Methamphetamine users who identify as heterosexual double their odds of being sexually active and were more likely to have multiple sexual partners and causal sex partners when they were using compared with when they were not using.  The effect was dose related. There was no association with reduced condom use however the authors surmised that the increased incidence of casual sex and multiple sexual partners among methamphetamine users increased the likelihood that they would have condom-less sex.

Previous research has focused very specifically on men who have sex with men (MSM) as a high-risk population for HIV transmission. Comparatively few studies have been conducted in heterosexual populations. This leaves a substantial gap in our understanding of how methamphetamine use might impact on HIV and other STI transmission at a population level. Although the risk of HIV transmission may be lower with heterosexual behaviour, the larger number of people affected may amount to a significant public health impact. This is a particularly important consideration in countries where heterosexual HIV transmission is dominant, and where there has been concern about the potential impact of increasing methamphetamine use on HIV rates

These findings suggest methamphetamine use is a potential factor in the heterosexual transmission of HIV and other STIs. STI and HIV prevention initiatives targeting heterosexual people who use methamphetamine are currently less well developed than those targeting MSM, and are likely to be challenged by lack of methamphetamine-specific treatment options and the relatively low levels of contact that people who use methamphetamine have with health services, particularly among those who smoke the drug.