OA4-AM24-TU-07 - The Relationship Between Rurality and Transfusion-Transmissible Infections Among Blood Donors and the Influence of Demographic Characteristics

The Transfusion-Transmissible Infections Monitoring System (TTIMS) includes ~60% of the US blood supply, combining data from four blood collection organizations to track demographic and TTI trends. TTIMS is used in this study to assess whether urban donors have different TTI risk compared to rural donors, and to determine the influence demographic differences may have on this relationship.

Study

Design/Methods:

Blood donation data from TTIMS were categorized as rural or urban based on donor zip code of residence using a Centers for Disease Control and Prevention definition. Allogeneic, directed, and COVID-19 convalescent plasma donations were included for a 3-year period (Oct 2020-Sep 2023), during which only a donor’s last donation was included to create a donor-level dataset. Donor demographics were compared by urban vs rural status using the Chi Square Test. For HIV, HBV, and HCV, donations were categorized as a consensus positive (CP) infection based on combinations of NAT and/or serology or as a recent infection (RI) for the subset of CP when only agent-specific NAT was reactive and confirmed; and for syphilis, donations were categorized as CP if antibody confirmed and as a syphilis active infection (AI) if CP donations further tested positive on a rapid plasma reagin test. Multivariable logistic regression models predicted the odds of TTIs based on the donor being from an urban vs a rural area.

Results/Findings:

Among 6,854,840 donors, 5,770,417 were categorized as urban (84.2%) and 1,084,423 as rural (15.8%). Donors from urban vs rural donors were more likely to be from men (46.8% vs 43.4%), under age 55 (65.2% vs 61.6%), non-White (23.4% vs 9.3%), a first-time donor (27.6% vs 23.7%), donating at a fixed site (29.2% vs 7.4%), and from the Southern US Census region (33.6% vs 24.8%). Urban compared to rural donors were 2.6 (95% CI: 2.1, 3.2) times more likely to have an HBV CP infection, 1.4 (95% CI: 1.1, 1.9) times more likely to have an HIV CP infection, 1.7 (95% CI: 1.6, 1.8) times more likely to have a syphilis CP infection, and 1.4 (95% CI: 1.3, 1.6) times more likely to have a syphilis AI in unadjusted models (Figure 1). When accounting for demographic characteristics, only the elevated HBV CP in urban vs rural areas retained significance. HCV CP was less likely to occur in urban vs rural areas only in the adjusted model (Odds Ratio: 0.8, 95% CI: 0.7, 0.9). Neither the adjusted nor unadjusted odds ratios for HBV RI and HCV RI were significant; there were no rural HIV RI to compare to the 6 urban RI cases.

Conclusions:

Urban donors were more likely to present with HBV CP, HIV CP, syphilis CP, and syphilis AI infections compared to rural areas. When controlling for demographic characteristics, these differences became smaller or no longer significant. These findings may inform blood collection organizations and researchers on TTI risk based on rurality.