Abstract
Despite an estimated risk of HIV infection from anti-HIV screened blood transfusions of less than one in 225,000 per unit, there continues to be strong pressure to implement additional donor screening and viral inactivation procedures. Decisions to implement such procedures must be based on analyses that incorporate accurate estimates of residual risk, and data-based projections for the reduction in risk that would result from each measure. Since the residual risk of HIV is primarily due to donations given in the infectious pre-seroconversion window, effort must be directed at: reducing donations by persons in this window; employing tests that narrow the window; and development and implementation of procedures that inactivate viral compartments that predominate during the window. Unfortunately, as the risk of HIV has declined to near-undetectable levels, the challenge of generating appropriate data to evaluate new measures, and thereby support rational policy decisions, has increased inversely. To meet this challenge, we must refine our understanding of the virological characteristics of early HIV seroconversion, and of the types of donors who present in the seroconversion window. Thoughtful application of a thorough understanding of the seroconversion window, in the context of accurate HIV incidence data in the donor settings, should enable us to assure the public of a safe blood supply while resisting inappropriate implementation of unnecessary and usually non-specific procedures.