Researchers in Belgium conducted a systematic review and update of available evidence regarding the risk of transfusion-transmissible infections (TTIs) in sexually active gay and bisexual male blood donors. The review also included available data in the wake of policy revisions from government regulators that resulted in the “easing” of deferral periods for sexually active gay and bisexual men.
The authors explained that “this is only one aspect that may inform decisions, and an analysis of all available resources to inform policy is outside the scope of this review.” They include three types of relevant studies in their review:
- “Type I studies: comparing the prevalence of TTI markers in blood products of [sexually active gay and bisexual men] versus [other eligible donors];
- Type II studies: comparing prevalence, incidence and/or residual risk in blood donors before versus after a change in the deferral period [for sexually active gay and bisexual male donors]; and
- Type III studies: comparing the number of [sexually active gay and bisexual men] in infected blood donors versus non-infected blood donors (case-control studies).”
The researchers included available data from January 2014 through February 2022 and blood donors or [individuals] eligible to give blood in “Australia, Canada, Denmark, France, Israel, Italy, Switzerland, The Netherlands, United Kingdom (UK), or the U.S. They [excluded] population[s] containing, but not exclusively consisting of, either blood donors or people eligible to give blood.”
The authors explained that four Type I studies were identified “suggesting that there may be an elevated risk of TTIs combined, HIV, syphilis, and hepatitis B virus (HBV) (core antibody but not surface antigen) in sexually active gay and bisexual men. But they note[d] that “the evidence is very uncertain due to study limitations, [that studies considering differential risk behave[o]r among [sexually active gay and bisexual men] are rare, and the subgroups of [sexually active gay and bisexual men] defined as those with ‘high-risk’ behavi[o]r in [such]studies are broader than what is currently being used in blood cent[er]s that adopt [individual donor assessments].
Nine Type II studies “assessed fluctuations in TTI risk in blood donors after easing the deferral period [ for sexually active gay and bisexual men.] One study suggested that easing the deferral period to one year may have little to no effect on TTI risk. Only one study focused on the effect of changing from a one-year to 3-month deferral and suggested that this may have little to no effect on HIV prevalence. However, the 95 percent CI was so wide that a threefold decrease/increase in HIV prevalence could not be ruled out. Another study estimated that adopting [individual donor assessments] may slightly increase HIV prevalence with a factor of 1.4, but not ruling out a twofold increase, compared to permanent deferral. The authors further explained that “[d]espite the large sample sizes used in these two latter studies, the imprecision in effect estimates (i.e., wide confidence intervals;) can (at least partly) be attributed to the low HIV prevalence in blood donors (which is, in turn, due to the low population risk and the use of stringent blood donor eligibility criteria).”
The researchers found 12 studies that fit the criteria for Type III. “[These studies] “suggested that [sexually active gay and bisexual men] may be a risk factor for HIV, but the certainty of evidence was very low. A statistically significantly increased risk of HBV, hepatitis C virus (HCV), or HTLV-I/II could not be demonstrated overall [except for one study showing a statistically significant risk of HCV in sexually active gay and bisexual men]. None of the Type III studies provided information on the time since last [sexual] contact with [gay and bisexual men], [the] number of sexual partners [except one study], or details on sexual risk behavi[o]r (e.g., anal sex, condom use).”
The review concluded that “several research gaps can be identified based on the currently available observational studies, especially when it comes to making practical recommendations…The current systematic review focuses on observational studies concerning TTI risk in [sexually active gay and bisexual male] blood donors and after easing the deferral for [these individuals]. When informing policy-making, other sources of currently available information should be used as well, including findings on compliance and donor comfort when using alternative questions, mode[l]ing studies, and surveillance reports. In addition, other criteria, including the feasibility and cost-effectiveness of alternative deferral periods, should be further examined and considered when making decisions.”
Citation: Schroyens, N., Borra, V., Compernolle, et al. “Men who have sex with men and risk for transfusion-transmissible infections in blood donors in Western countries: A systematic review update.” Vox Sanguinis. 2023.