Emilya Huseynova, MD, MPH: No financial relationships to disclose
Background/Case Studies: The Transfusion-Transmissible Infections Monitoring System (TTIMS) established in 2015 is composed of 4 large blood collection organizations (BCOs). TTIMS monitors blood safety by assessing transfusion-transmitted pathogen trends in ~60% of the US supply. Donors with perceived high-risk behaviors, including males responding yes to having sex with other men (MSM) were deferred for 12 months from 2016-2020 (12M) and 3 months from 2020-2023 (3M), prior to the implementation of the individual donor assessment (IDA) in which specific MSM questions were removed from the donor health questionnaire, along with other changes coincident with 3M deferrals (e.g., many high-risk sexual behaviors and injection drug use). Here we evaluate HIV, HBV, and HCV donation prevalence (Prv), donor incidence (Inc) and per donation residual risk (RR) from 2015-2023, including time-limited 12M and 3M periods.
Study
Design/Methods: Annual Prv was assessed for 8 TTIMS years (each starting on Oct 1 of a year and ending on Sep 30 of the next year) from 2015-2023. HIV, HBV, and HCV Prv/100,000 (pht) donations was calculated based on serology and nucleic acid testing (NAT) results. Linear regression assessed Prv using one-year intervals. Two ~3-year periods were selected between 2017 and 2023, based on BCO-specific 3M implementation dates, to evaluate Inc differences around FDA’s deferral policy change from 12M to 3M. Repeat (RPT) donor Inc was measured using classic methods. First-time (FT) Inc was estimated using NAT yield ratio of FT/RPT donors with overall (OVRL) weighting for total Inc (Steele et al. Transfusion 2021;61-839). Period-specific calculations were required due to the influence of the COVID-19 pandemic on the distribution of FT and RPT donors and donations (Conti et al. Transfusion 2024). RR, defined as the chance of collecting a donation during the window period (WP), was calculated by multiplying agent-specific Inc by the WP. Fisher’s exact test was used to evaluate Inc changes (α=0.05).
Results/Findings: Annual HCV Prv decreased (19.7-9.6 pht) from Years 1-8 (R2=0.89, p< 0.01). Changes in HIV (2.5-2.1 pht) and HBV (6.3-6.6 pht) Prv were not significant. All (RPT, FT, OVRL) HIV and HCV Inc decreased from 12M to 3M (p< 0.0001). No change was detected in HBV RPT Inc while FT and OVRL weighted Inc declined (p< 0.0001). For all agents, RR remained either constant (HBV RPT) or decreased from 12M to 3M (Table).
Conclusions: Even though donor deferral periods were reduced for many infection risk behaviors, HIV and HBV Prv were stable over 8 years of TTIMS and HCV Prv declined. Inc and WP RR for all 3 agents remained similar or decreased during the 12M and 3M deferral periods with estimated OVRL WP RR remaining at ~1:2 million donations or lower in both periods. Thus, changes in policy did not appear to adversely impact the safety of the blood supply.