Prevention of transfusion transmitted infections

Michael P. Busch, Evan M. Bloch and Steven H. Kleinman


Since the 1970s, introduction of serological assays targeting virus-specific antibodies and antigens has been effective in identifying blood donations infected with the classic transfusion-transmitted infectious (TTI) agents (HBV, HIV, HTLV-I/II, HCV). Subsequently, progressive implementation of nucleic acid-amplification technology (NAT) screening for HIV, HCV, and HBV has reduced the residual risk of infectious window period donations, such that per unit risks are <1 in 1,000,000 in the US, other high-income countries, and in high incidence regions performing NAT. NAT screening has emerged as the preferred option for detection of newer TTI agents including West Nile virus, Zika virus, and Babesia microti. While there is continual need to monitor current risks due to established TTI, ongoing challenges in blood safety relate primarily to surveillance for emerging agents coupled with development of rapid response mechanisms when such agents are identified. Recent progress in development and implementation of pathogen reduction technologies (PRT) provide the opportunity for proactive rather than reactive response to blood safety threats. Risk-based decision-making tools and cost-effectiveness models have proved useful to quantify infectious risks and place new interventions in context. However, as evidenced by the 2015-2017 Zika virus pandemic, a level of tolerable risk has yet to be defined in such a way that conflicting factors (e.g. theoretical recipient risk, blood availability, cost, and commercial interests) can be reconciled. A unified approach to TTIs is needed, whereby novel tests and PRT replace rather than add to existing interventions, thereby ameliorating cost and logistical burden to blood centers and hospitals.

  • Submitted November 21, 2018.
  • Accepted February 3, 2019.