Globally, HIV and other sexually-transmitted infections (STI) account for 6.3% of the burden of disease and alcohol for 4%, similar to that caused by tobacco (4.1%) and high blood pressure (4.4%) [1
]. In some sub-Saharan countries, such as South Africa, for example, the burden attributable to these conditions is even greater - HIV and other STI constitute about a third of disease and alcohol an estimated 7.9% [2
]. Overall, much of sub-Saharan Africa carries a massive burden of HIV and of alcohol disease, and these pandemics are inextricably linked. The conditions share many common determinants and together exacerbate the underlying socio-economic inequalities in this region. As we discuss in this article, alcohol disease and HIV have an especially intimate link: alcohol has independent effects on decision-making concerning sex, and on skills for negotiating condoms and their correct use. Thus far global initiatives to prevent HIV and other sexually transmitted infections (STI) have largely ignored the potential mediatory role of alcohol in unsafe sex (for example, note that the list of WHO HIV prevention priorities does not mention alcohol) [3
Alcohol use results in a considerable range of diseases, the occurrence of which is contingent upon three factors: lifetime cumulative volume consumed; patterns of drinking; and drinking contexts [4
]. Overall lifetime volume of alcohol is linked to chronic social problems (such as unemployment) and to chronic diseases such as alcoholic liver cirrhosis. By contrast, pattern of drinking (amount per drinking episode), in particular frequent episodes of intoxication, is a powerful mediator of acute problems such as accidents, interpersonal violence and high-risk sexual behaviour [5
]. Context of alcohol use is also a critical determinant of its consequences, as opportunities for sexual encounters and for drinking alcohol often co-exist in both social dynamics and physical locations [7
]. This means that the impact of alcohol use on acute social behaviours (including sexual behaviours [11
]) is shaped more by the 'how'
of alcohol consumption, [10
] than by the frequency of drinking or cumulative lifetime volume of alcohol.
Unlike settings with low-risk drinking patterns (classically southern European patterns of drinking with meals), sub-Saharan Africa is characterised by harmful patterns of drinking. This includes the use of large quantities of alcohol per occasion, but also drinking to intoxication in public spaces, heavy drinking during cultural festivals and drinking outside of mealtimes [12
]. These patterns often take the form of weekend binge drinking [6
] and are true of both rural and urban areas, and across all social strata [14
]. It follows that acute rather than chronic alcohol problems predominate in sub-Saharan Africa, and include road traffic accidents, crime, interpersonal violence and unsafe sex, afflicting harm to self and others. Globally, drinking alcohol has been linked with an increased number of sexual partners, regretted sexual relations, inconsistent condom use, condom accidents and an increased incidence of STI [6
]. Studies in sub-Saharan Africa, in particular [8
], have found strong associations between alcohol consumption and unprotected sex, early sexual debut, multiple sex partners and having an STI [6
HIV and alcohol also share common ground with sexual violence. A person's risk of rape or of perpetrating rape increases during heavy drinking episodes. Both perpetrators and victims of sexual violence have a high likelihood of having drunk alcohol prior to the incident, possibly because alcohol intoxication makes the drinker an easier target for potential perpetrators [21
More than 20 studies in Africa have reported higher occurrence of HIV among people with problem drinking [8
]. A meta-analysis of these studies found that compared with non-drinkers, non-problem drinkers had 1.6 fold higher HIV prevalence, while problem drinkers had a 2.0 fold higher prevalence [23
]. This finding is strongly consistent across studies and is similar among women and men.
Challenging evidence for a causal relationship between alcohol, unsafe sex and HIV, are some studies which suggest that personality factors such as impulsivity or sensation seeking, as well as contextual factors confound the alcohol and sex relationship [24
]. It must be acknowledged that the relationship between alcohol use and risky sex is complex and that associations between HIV and alcohol use may, at least in part, be accounted for by the fact that heavy drinkers are inherently different from other population groups [27
]. Overall, however, in recent years the causal pathway between alcohol intoxication, unsafe sex and HIV acquisition has become more clearly defined and the evidence increasingly compelling [9
An argument can be made that alcohol is an intermediate factor on the causal pathway between certain personality types and unsafe sex (see figure ). Thus people with impulsive personalities, for example, may still have unsafe sex when not influenced by alcohol, just as this group of people may drive dangerously when sober. However, reducing harmful drinking in this population would alleviate a portion of their unsafe sex, just as curbs on drinking and driving reduce a substantial portion of their road traffic accidents. Although few would accept the theory that personality types completely explain the association between alcohol use and outcomes such as road traffic accidents, crime and sexual violence, more evidence is required to determine whether associations between alcohol and unsafe sex are confounded by personality types or if alcohol mediates this relationship.
Figure 1 Do personality types confound associations between alcohol and unsafe sex or is alcohol an intermediate factor on the causal pathway between personality and unsafe sex?. In the confounding theory, the association between heavy drinking episodes and unsafe (more ...)