Sydney

A study from a cohort of 1427 HIV-negative gay men in Sydney, the HIM study, found that while serosorting and other sexual harm-reduction (SHR) practices are considerably less protective against HIV than using condoms, they are better than having no strategy at all. During the four-year study, 53 men (0.78% a year) were diagnosed with HIV.¹

The study looked at four SHR behaviours: serosorting was practised by 38% of the total group; negotiated safety (defined as serosorting within a primary relationship, involving a clear agreement not to have unprotected sex outside the relationship) by 25%; strategic positioning by 15%; and withdrawal by 13%.

Men who were inconsistent condom users, but practised serosorting, were 2.2 times more likely to acquire HIV than men who consistently used condoms. This finding was not quite statistically significant. Men who combined serosorting with other sexual harm-reduction practices, such as strategic positioning, were actually worse off, being three times more likely to become infected. Withdrawal as an SHR method, which was practised by 13% of men, was particularly and significantly ineffective, with men who practised this as their sole method being five times more likely to acquire HIV than condom users.

However, men who used no sexual harm-reduction strategies at all were eleven times more likely to acquire HIV than condom users, implying that SHR strategies were helping to prevent a significant proportion of infections in men who did not use condoms consistently.

The researchers commented that each risk-reduction behaviour offered “substantial but incomplete protection against HIV infection”.

Noting that Sydney is one of the few places in the developed world that has not had recent increases in HIV diagnoses in gay men, and that incidence was relatively low in this study, despite high overall levels of unprotected sex, they suggested that “risk reduction behaviours can be associated with some success in containing HIV at the population level”.

In an accompanying editorial, Fritz van Griensven of the Centers for Disease Control and Prevention suggested that some of the specific characteristics of the gay community in Sydney may have allowed for this success.² Specifically, the rate of HIV testing was one of the highest in the world, allowing accurate knowledge of HIV status. Moreover, a strong gay community may have helped reduce stigma and discrimination, he added.