(P-PH-7) Risk factors for recent HIV infection in US blood donors in the period 2015 - 2022

Background/Case Studies: Monitoring HIV infection risk in donors helps identify potential threats to blood supply safety. This study assessed behavioral and demographic correlates of recently acquired, recent (R), and long-standing (LS) HIV infections in US blood donors.

Study

Design/Methods: A case-control analysis of risk factors collected by telephone interview in donors with confirmed HIV infection (nucleic acid testing (NAT), serology, or both) (cases) and those false-positive for anti-HIV or HBsAg (controls) with donation dates from 09/2015–12/2022 was conducted. If available, plasma samples from cases were tested using a limiting antigen (LAg) avidity assay to classify NAT and seroreactive infections as R or LS; with R likely acquired within 6 months before donation. HIV NAT-yield and LAg avidity recent infections were classified as R and all others as LS. Bivariable and multivariable (MV) logistic regression were used to compare demographics and behaviors in the 12 months before donation. Responses with bivariable significance of p< 0.1 were included in sex-specific MV models and defined as significant if 95% Confidence Intervals (95% CI) of adjusted odds ratios (aOR of cases vs controls) in the MV models excluded 1.

Results/Findings: Most case and control interviews are from the period with 12-month behavioral deferrals; 16% of case interviews are from the period when 3-month deferrals were adopted (mid-2020). Responses were obtained from 42 R, 154 LS, male (M) and 13 R, 60 LS, female (F) HIV cases and 242 M and 266 F controls. For M, risk factors were similar for R and LS; aOR were significant for income, sexual orientation, 4+ sex partners, sex partner of men who have sex with men (MSM), and body fluids exposure (Table). For F, aOR for R and LS differed, with only 4+ sex partners and MSM sex partner significant for R.

Conclusions: Risk factors for HIV are consistent for R and LS HIV infections in M but appear to differ for F. For both sexes, non-disclosure of deferrable risk behavior is evident. In addition, infection is associated with higher number of sex partners, especially for recently acquired HIV.

Importance of research: This work reports ongoing surveillance of transfusion-transmissible HIV infections in the blood supply. Monitoring of nearly 60% of the US blood supply enables changes in risk to be identified. Data were compared following changes in blood donation guidelines and risk factor exposure collected directly from blood donors following identification of interdicted units shortly following donation.