Abstract Body

In 2015, the FDA published revised guidance that recommended a change in donor deferral policy for men who have sex with men (MSM) from indefinite to one year. The Transfusion Transmissible Infections Monitoring System (TTIMS) has monitored HIV, HBV and HCV infections in four blood collection organizations since 2015, representing approximately 60% of the US blood supply. We evaluated HIV-1 incidence changes in first-time blood donors following the implementation of the new MSM deferral policy using biomarkers of recent infection.

We utilized an algorithm to identify recent HIV infections amongst 5.7 million first-time donors (NAT-positive/Ab-negative or by applying the LAg Avidity EIA and viral load testing to seropositive donations). We derived a context-specific mean duration of recent infection using a novel Bayesian method and a false-recent rate, and utilized these parameters to estimate incidence rates and incidence rate differences in first-time donors during the 15-month periods preceding and following the deferral policy implementation, as well the entire post-implementation period through end 2018. We used Poisson regression models to identify demographic covariates of incidence.

Overall HIV incidence in first-time donors in the 15 months prior to the MSM deferral policy implementation was estimated at 2.63 cases/100,000PY (95% CI: 1.44–3.81), in the 15 months after at 3.19 (1.94–4.43) and in the entire period after at 2.59 (1.71–3.48). Incidence differences were not statistically significant for either comparison. The figure shows incidence difference estimates by sex, age group, race/ethnicity and public health region. Of these, only the Western region showed a marginally significant increase, which becomes non-significant when the post period is expanded to include all available data. Bivariable and multivariable Poisson regression models using data from the entire TTIMS period showed that MSM deferral policy was not a significant correlate of incidence, although male sex (risk ratio 5.0, 95% CI: 2.8–9.5), age 18-24 (RR: 4.3, 1.5–18.3), black race (RR: 10.1, 5.8–17.9), Hispanic ethnicity (RR: 2.6, 1.3–5.0) and Southern region (RR: 2.0, 1.4–7.9) were significant.

There is no evidence that the implementation of a 12-month MSM deferral policy resulted in increased HIV incidence in, and therefore transfusion transmission risk from, first-time blood donors in the United States.