HIV in Canada: A primer for service providers

 

Serosorting for HIV-negative people

Key Points

  • For HIV-negative people, serosorting often refers to choosing to have sex only with people they believe to be HIV negative (called HIV-negative serosorting).
  • HIV-negative serosorting fails to protect against HIV when both people are not actually HIV negative.
  • Serosorting can also mean choosing partners based on their HIV status combined with the use of a highly effective prevention strategy; if a highly effective strategy is used consistently and correctly, there is little to no risk of HIV transmission.  

For HIV-negative people, serosorting often refers to choosing to have sex only with people they believe to be HIV negative (called HIV-negative serosorting).

In theory, HIV-negative serosorting should prevent HIV because there is no possibility of HIV transmission if both partners are HIV negative. However, if one partner is actually HIV positive (but does not know it), serosorting has no protective effect and there is a high risk for HIV transmission.

Using serosorting based on HIV-negative status can be unreliable because it is hard to be sure of someone’s current HIV status. In Canada, it is estimated that 14% of people with HIV are unaware that they have the virus. Even with frequent HIV testing it can be difficult for a sexually active person to be certain that they do not have HIV if they are having ongoing potential exposures to HIV. This is because HIV needs to be in the body for a certain length of time before HIV tests can detect an infection during the window period for the test. Depending on the test used, this can take up to three months. A person can only be sure they are HIV negative if they receive a negative test result and had no potential exposures to HIV during the window period for the test. Meeting these criteria can be challenging, particularly for individuals who may participate in unprotected sex (where no highly effective prevention strategy is used) or share drug use equipment on a regular basis. For serosorting to work in the absence of highly effective prevention strategies, both partners need to be sure of their HIV status.

Because of advances in HIV prevention technologies in recent years, some people have redefined serosorting to include choosing partners based on HIV status combined with the use of a highly effective strategy. For example, someone who is HIV negative might choose a sex partner who is HIV positive and on treatment with an undetectable viral load. When choosing partners based on the use of a highly effective prevention strategy, it is important that the strategy is used consistently and correctly to effectively prevent HIV transmission. If a highly effective strategy is used consistently and correctly, there is little to no chance of HIV transmission.

Resources

Does serosorting prevent HIV transmission in men who have sex with men?Prevention in Focus

Choosing Partners with the Same HIV Status (Serosorting) – US Centers for Disease Control and Prevention (CDC)

Sources

  1. Purcell DW, Higa D, Mizuno Y, et al. Quantifying the harms and benefits from serosorting among HIV-negative gay and bisexual men: A systematic review and meta-analysis. AIDS and Behavior. 2017 Oct;21(1):2835–2843.
  2. Vallabhaneni S, Li X, Vittinghoff E, et al. Seroadaptive practices: Association with HIV acquisition among HIV-negative men who have sex with men. Plos One. 2012 Oct 3;7(10):e45718. Available from: https://doi.org/10.1371/journal.pone.0045718
  3. Public Health Agency of Canada. Summary: Estimates of HIV Incidence, Prevalence and Canada’s Progress on Meeting the 90-90-90 HIV targets, 2016. Public Health Agency of Canada, 2018. Available from: https://www.canada.ca/en/public-health/services/publications/diseases-conditions/summary-estimates-hiv-incidence-prevalence-canadas-progress-90-90-90.html