#OA4-AM25-TU-20 - HIV Incidence and Factors Associated with Recent Infection Among Blood Donors in Brazil Following Adoption of Individual Donor Assessment

In mid-2020, Brazil replaced time-based deferral for men who have sex with men (MSM) with individual donor assessment (IDA). Unlike other countries, Brazil applies broader behavioral criteria, deferring donors with a new, multiple, or concurrent sexual partner, regardless of sexual practice. We conducted the first evaluation of HIV incidence among Brazilian blood donors post-IDA and assessed factors associated with recent infection among confirmed HIV-positive donors.

Study

Design/Methods:

Between April 2020 and April 2024, we analyzed donations from five public blood centers in São Paulo, Belo Horizonte, Rio de Janeiro, Recife, and Manaus, representing geographically diverse regions of Brazil. Of the HIV screening–reactive donations identified by NAT and serology testing, residual volumes were available for 76% and were sent to the U.S. for additional testing, including Ortho HIV 1-2 Ag/Ab, Sedia Limiting Antigen (LAg) avidity assay, and Hologic Aptima quantitative HIV viral load (VL). Recent infection was defined as: (1) Ortho-reactive, LAg-recent, and VL >200 copies/mL; (2) Ortho-nonreactive with VL >200 copies/mL; (3) NAT-yield donations. HIV incidence was estimated using a cross-sectional method for first-time donors (FTD) and the person time approach for repeat donors (RD). Factors associated with recent infection were assessed using multivariable logistic regression, adjusted for sex, age, race/ethnicity, education, donation type, blood center, and calendar year, and limited to confirmed HIV-positive donors with complete recency data.

Results/Findings:

Among ~1.6 million donations, 1,909 HIV screening–reactive samples underwent further testing. Of these, 853 unique donors were confirmed HIV-positive, and 95 (11%) met criteria for recent infection. HIV incidence was estimated at 1.8 per 10,000 person-years (py) (95% CI: 1.2–2.6) for FTD and 1.45 per 10,000 py (95% CI: 1.27–1.63) for RD. Among confirmed HIV-positive FTD, recent infection was significantly more likely among males (aOR: 2.66; 95% CI: 1.04–6.80) compared to females. Significant associations were not observed for age, race/ethnicity, education level, donation type, blood center, or calendar year.

Conclusions:

Overall, our findings provide reassurance that the implementation of IDA in Brazil has not led to increased HIV incidence among blood donors compared to pre-IDA. Recent infections are more likely among male FTD, consistent with previous studies. The lack of variation across calendar years and blood centers suggests that the risk profile of donors with recent HIV infection has remained stable, likely reflecting persistent social and behavioral factors that donor education efforts have not resolved. Continued surveillance is essential to monitor the long-term impact of IDA.