Medical Director Donation Policy & Studies, Canadian Blood Services Ottawa, Ontario, Canada
Background/Case Studies: The blood donor screening questionnaire is important in ensuring recipient safety. Donors are deferred if they are on antiretrovirals (ARV)as post-exposure or pre-exposure prophylaxis (PEP or PrEP) for HIV as there is a risk of undetected HIV infection. We assessed donor compliance by measuring ARV levels in selected anonymized donor samples collected from September 22, 2022 to December 31, 2024, almost all after the introduction of gender-neutral sexual risk behavior screening.
Study
Design/Methods: EDTA plasma samples collected at the time of donation (retention samples) were retrieved, frozen, and shipped for measurement of tenofovir and emtricitabine concentrations. Samples were from randomly selected first time male donors in large urban areas (n=520), syphilis (n=133) or HIV (n=5) confirmed positive donors, and donors deferred for PEP/PrEP use on a previous donation attempt who returned to successfully donate (n=225 samples from 115 unique donors).
Results/Findings: ARVs were not detected in all samples from first time male donors, HIV positive donors, syphilis positive female donors and female donors previously deferred for PEP/PrEP . Three of 110 male syphilis positive donors (2.7%) and 14 of 85 male donors previously deferred for PEP/PrEP (16.5%) had detectable tenofovir and/or emtricitabine levels, suggesting recent PrEP or PEP use. Eleven of these donors were tested multiple times and 10 had ARVs detected more than once.
Conclusions: Results on syphilis positive male donors were similar to findings in England and the Netherlands. Noncompliance with criteria for ARV use was high in male donors previously deferred for PEP/PrEP. Messaging regarding recipient safety is particularly difficult in this group, since it is at odds with public health messaging about reduction in individual HIV risk due to use of PrEP/PEP.
