California study contests belief that saunas facilitate HIV transmission

Most gay and bisexual men do not engage in high-risk HIV transmission behaviour in saunas or bathhouses according to a study from the University of California, San Francisco published in the June 1^st edition of the Journal of Acquired Immune Deficiency Syndromes. The study’s results – which found that some men who reported recent high-risk behaviour in other settings actually had safer sex at the sauna – contest the long-held belief that saunas facilitate HIV transmission on a large scale.

It has been a long-held assumption that saunas (known in the United States as bathhouses) facilitate high-risk sex amongst gay and bisexual men. Although previous studies have suggested that saunas attract men who visit a variety of public sex environments, a recent study from Australia suggested that there are different kinds of risk attached to particular types of public sex venues, and that men who had sex in the backroom of a bar or club were nine times more likely than men who had sex in saunas to have unprotected anal intercourse (UAI).

Investigators from the Center for AIDS Prevention Studies, at the University of California, San Francisco used a rigorous probability sampling method to ascertain for the first time men’s HIV risk behaviour while at the sauna, compared with their HIV risk behaviour elsewhere in the three months before their sauna visit.

The study was conducted in the last five weeks of 2001 in what the investigators describe as a “typical North American gay bathhouse”. The participants were a sample of men who were chosen at random on their way out of the sauna. Their responses were weighted to make sure these men were as representative as possible of the entire sauna-visiting population. Participation was voluntary, anonymous, and reimbursed.

Almost one in twelve of the 440 respondents reported that they did not have any sex (i.e. anal or oral sex) during the visit, and the rest (91.5%) reported that they engaged in oral sex during their visit. A total of 44% reported anal sex: 33% had protected anal sex only, and 11% reported UAI. Of these 44%, more men reported having insertive anal sex (29% protected only and 7% unprotected at least once) rather than receptive anal sex (14% protected only and 5.5% unprotected at least once).

Among the 158 men who engaged in insertive anal sex, one in five reported doing so without a condom at least once. Among the 85 men who engaged in receptive anal sex, 28% did so without a condom at least once. Just over half (52%) of the 24 men who had receptive UAI were HIV-positive, whereas fewer than one in three (29%) of the 31 men who had insertive UAI were HIV-positive.

In contrast, more than one in four of the 440 men (27.5%) reported having UAI in the three months before their sauna visit. Almost twice as many men reported having had UAI in private than in public (21.5% versus 12.5%; p

Of the men who engaged in UAI in the previous three months, a quarter (24%) also engaged in UAI during their visit to the sauna, whereas only 5% of the men who did not engage in UAI in the previous three months engaged in UAI during their visit to the sauna (p

Of the 403 men who reported oral or anal sex at the sauna, men who reported UAI in private or in public in the past three months, and men had been to a sauna in the past year, were more likely to report UAI during the current visit.

The investigators note that “most men at the bathhouse did not engage in risk behaviour anywhere at all – not at the bathhouse, not at other sex settings, and not in private settings such as a home or hotel...Surprisingly, a number of men who reported recent high-risk behaviour in other settings actually reported safer sex during their current bathhouse visit. These study results contradict the assertion that the bathhouse facilitates large-scale high-risk sex.”

They argue that, “the vast majority of the sexual activity that occurred in the setting would not contribute to HIV transmission, even though some men at the bathhouse persist in risk behaviour not only at the bathhouse but in private and other public settings.”

Pointing out that “men who engaged in UAI tended to do so wherever they had sex,” they conclude that saunas are “a point of access to reach these men with appropriate intervention” and that “public health has the opportunity to design innovative prevention interventions that men can take with them and that target reducing their risk behaviour not only at the bathhouse but wherever they have sex.”