What Is Serosorting?
In their Spring 2014 Prevention in Focus article, James Wilton and Tim Rogers provide a great review of the current research on serosorting. In their article, they define serosorting as using a potential partner’s HIV status as a determination as to whether or not any (or just high-risk) sexual relations should occur. For example, HIV negative individuals could choose to only have sex without a condom with other HIV negative partners, or HIV positive individuals could choose to only have condomless sex with other HIV positive partners. Historically, it has been used primarily by men who have sex with men (MSM). It is a fairly common transmission prevention strategy, as 14 to 44 percent of HIV positive men and 25 to 38 percent of HIV negative men in the United States, Australia and Europe report using the serosorting strategy.
How Effective Is Serosorting?
The effectiveness of serosorting strategies has been the subject of numerous studies. In their review, Wilton and Rogers highlight the largest study that sampled over 12,000 MSM men in America, conducted by Vallabhaneni and colleagues. The focus of the study was HIV negative serosorting, defined as HIV negative men engaging in condomless anal sex with only men who they thought to be HIV negative. The study found that the prevalence of infection among HIV negative serosorters was 57 percent lower than with those who engage in condomless anal sex with partners of unknown HIV status. However, it also revealed that risk of HIV infection among HIV negative serosorters was 82 percent more likely than among those who did not engage in any condomless anal sex. Possible reasons for this difference could be the sometimes incorrect perceptions of HIV status that individuals have for themselves or their partners as we will discuss further in the next section.
A common concern with HIV positive serosorters is the concept of “superinfection,” or re-infection with a new strain of HIV. If the new strain is medicine-resistant, it can interfere with the treatment method in place (if there is one). The rate of re-infection occurrence is still in question. Some studies report it is rare, while others suggest it happens at equivalent rates as initial HIV transmission.
When Serosorting Goes Awry
Wilton and Rogers noted two main reasons the effectiveness of the serosorting strategy can be reduced, both concerning miscommunication. Miscommunication of HIV status can result in an absence of discussion and disclosure, leading to sexual partners making assumptions about status based on heuristics. Miscommunication of HIV status can also occur when an individual inadvertently discloses an incorrect status, such as when an individual believes his/her own status is HIV negative when in fact it is unknown or positive. The effectiveness of serosorting depends heavily on knowing one’s status and proper communication.
Everyone Can Serosort
While most of the serosorting research is with MSM, this can be a strategy employed by everyone who is sexually active. Serosorting as a practice is helpful because it encourages regular testing for sexually transmitted diseases and open conversations about disease status. While having sex with a condom will always be safer than condomless sex, for those individuals who are considering to have condomless sex with their partners (e.g., because pregnancy is not a concern and/or for pleasure) serosorting could be one further safeguard against transmission of disease. While there are risks associated with misinformed serosorting, if more sexually active individuals regularly got tested and disclosed their statuses with new partners in order to determine whether condomless sex is an option, HIV transmission rates (and likely rates of other sexually transmitted infections) could be greatly reduced.