Major reduction in occurrence of anti-c and anti-E in pregnancy after more than 10 years of preventive matched transfusion with most benefit for c-matching.

Extension with cE-matching of the transfusion policy for women under 45 years to prevent alloimmunization and hemolytic disease of the foetus and newborn (HDFN) was evaluated. After implementation of cEK-matching, anti-c occurrence decreased from 46.8 to 30.4 per 100 000 pregnancies (RR 0.65, 95% CI 0.54-0.79), while anti-E occurrence decreased from 122.1 to 89.9 per 100 000 pregnancies (RR 0.74, 95% CI 0.66-0.84). The c-negative women showed a higher anti-E occurrence before cEK-matching and a more pronounced decline with the new policy. This indicates that cEK-matched transfusion effectively reduces alloimmunization, and that a cK-matched approach could prevent most transfusion-related alloimmunization and HDFN.

How do we conduct a national transfusion related lookback program?

BACKGROUND: Lookback investigations are conducted by blood services when a risk of transmission of infection from a donor to a recipient has been identified. They involve tracing transfusion recipients and offering them testing for the relevant infectious agent. Results are relayed to the recipient to provide reassurance that there has been no transmission or to ensure appropriate treatment and care if required, and blood services are able to learn lessons from the planning, delivery, and outcomes of the investigation. A national lookback exercise was conducted in Scotland following the introduction of a test to identify occult hepatitis B infection, as recommended by the UK Advisory Committee for the Safety of Blood, Tissues and Organs (SaBTO) in 2021. METHODS AND MATERIALS: This paper outlines the development and delivery of a national lookback program. It discusses the logistical, economic, ethical, regulatory, and scientific issues that were considered during the planning and delivery of the lookback exercise. RESULTS: Development and delivery of a national lookback required robust governance, engagement of all relevant stakeholders and a shared understanding of aims, effective communication, systems, resources, limitations, and project management. Outcomes included a high testing uptake, low levels of reported anxiety, and a comprehensive data set. CONCLUSION: Key aspects for delivery of a successful large-scale lookback program include a patient-centered approach, clear and accessible communication, and whole-systems multiagency collaboration. Major challenges include stakeholder engagement and capacity.

Implementing pathogen reduction technology while discontinuing blood donor deferral criteria for sexual risk behaviors: A simulation study.

BACKGROUND: Combining pathogen reduction technology (PRT) with blood screening may alleviate concerns over the risk of transfusion-transmitted infections (TTI) and support changes in blood donor selection to potentially increase blood availability. This study aimed to estimate the residual risk of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) transfusion-transmission in Canada after implementing PRT, while eliminating deferrals for sexual risk behaviors. STUDY DESIGN AND METHODS: A probabilistic approach that combined Bayesian networks with Monte Carlo simulations was used to estimate the risk of transfusing HIV-, HBV-, or HCV-contaminated blood components. Different scenarios were considered to compare the current residual risk after PRT implementation, with and without donor deferral criteria for sexual risk behaviors. Donor profiles and blood component outcomes were simulated based on a literature review including the prevalence and incidence of HIV, HBV, and HCV in the Canadian blood donor population; the use of current blood screening assays; and HIV, HBV, and HCV blood donor viral loads. RESULTS: In the universal PRT scenario (i.e., with PRT/without deferral criteria), the estimated risks of HIV, HBV, and HCV transmission were significantly lower than those in the currently observed scenario (i.e., without PRT/with deferral criteria). CONCLUSIONS: This risk model suggests that PRT for platelets and plasma (and eventually for RBCs when available) significantly reduces the residual risks of HIV, HBV and HCV transfusion-transmission and could enable the removal of blood donor deferral criteria for sexual risk behaviors.

Notification and follow-up of blood donors reactive for transfusion-transmitted infections: A narrative review of the literature from India.

BACKGROUND AND OBJECTIVES: Notifying blood donors of their reactive status for transfusion-transmitted infections (TTIs) plays a vital role in enabling early diagnosis and management while also preventing these donors from making future donation and transmission of the infectious agent. Given the limited data on donor notification processes in India, a narrative review was conducted to assess the existing notification process and identify areas requiring enhancement. MATERIALS AND METHODS: We conducted literature searches using PubMed, Google Scholar and Scopus, employing various keywords. The review included data on the year of the study, study design, donor numbers, TTI screening methods, sero-reactive donor confirmation, notification frequency and methods, donor responses, post-test counselling and risk factor assessment. RESULTS: Out of the 29 identified articles, 16 studies were included in the analysis. Repeat testing for initially reactive results was conducted in nine studies for 24.3% reactive donors. Phone calls were the primary notification method in most studies (8; 50%), with letters sent in cases of no response. Only 12 studies provided data on notified donors, revealing a notification rate of 71.2%. Of all initially reactive donors, 33.3% sought post-test counselling. Data from six studies indicated that 74.3% of responsive donors had identifiable TTI risk factors. CONCLUSION: Our review revealed significant variability in the notification processes across different studies. To enhance the management of TTI-reactive donor notifications and responses, we recommend the establishment of universal protocols encompassing pre-donation counselling, repeat/confirmatory testing, notification methods and comprehensive follow-up and treatment.

A national surveillance system for continuous monitoring of blood transfusion safety: German haemovigilance data.

BACKGROUND AND OBJECTIVES: Haemovigilance (HV) systems aim to improve transfusion outcomes in patients and donor safety. An important question for blood regulators is how to ensure an effective HV system. MATERIALS AND METHODS: We retrospectively analysed the HV reports submitted to Paul-Ehrlich-Institut over the last two decades. RESULTS: Between 2011 and 2020, 50.86 million units of blood components were used, and 8931 suspected serious donor and recipient adverse reactions (SARs), 874 serious adverse events (SAEs) and 12,073 donor look-backs were reported. Following implementation of specific risk-minimization measures (RMMs) between 2000 and 2010, SAR reporting rates decreased for transfusion-transmitted viral infections (TTVIs), transfusion-related acute lung injury (TRALI) and transfusion-transmitted bacterial infections (TTBIs), while increasing for other serious adverse transfusion reactions. Within this decade, the overall blood component use decreased. CONCLUSION: Long-term data collection forms the basis to establish trends and changes in reporting and to evaluate the effect of RMM. Standardized criteria for reaction types, seriousness and imputability assessments and availability of a denominator are important elements. Central data collection and independent assessment allow for monitoring HV data in a nationwide context over time. Stakeholder involvement and transparent feedback on the benefit of RMM will help to achieve the objectives of HV.

Managing the risk of transfusion-transmitted malaria from Australian blood donations: Recommendation of a new screening strategy.

BACKGROUND AND OBJECTIVES: To reduce the risk of transfusion-transmitted malaria (TTM) from transfusible components, Australia tests for malaria antibodies in both travellers returning from and former residents of malaria-endemic areas. The testing is performed a minimum of 120 days after last potential exposure. TTM is an extremely rare event and managing the risk adds considerable complexity. The objectives of this study were to analyse various testing and deferral strategies, considering the risk, donation numbers and operational complexities. MATERIALS AND METHODS: A residual risk model was developed to calculate the risk of TTM in five testing/deferral strategies. Australian blood donor data from 2020 and 2021 were used and incorporated the incidence of parasitaemia, Plasmodium species and the malaria enzyme immunoassay test's failure rate. Donor and donation loss or gain and an operational assessment were performed. RESULTS: The current model's estimated risk of TTM is 1 in 67.9 million transfused units. Testing residents with a 120-day plasma restriction for visitors without testing was found to have the same estimated risk, with an expected increase of 342 donations per year, significant cost savings and a 62% reduction in the number of donors requiring assessment. CONCLUSION: A strategy that involves testing residents of malaria areas only and a 120-day plasma travel restriction would not significantly increase the risk of TTM, is operationally simpler, costs less and results in a small increase in donations.

The International Society of Blood Transfusion (ISBT) Public Health Research Toolkit: A report from the Surveillance, Risk Assessment and Policy Sub-group of the ISBT Transfusion Transmitted Infectious Diseases Working Party.

BACKGROUND AND OBJECTIVES: Data provided from blood donors have contributed to the understanding of public health epidemiology and policy decisions. A recent example was during the severe acute respiratory syndrome-related coronavirus (SARS-CoV-2) pandemic when blood services monitored the seroprevalence in blood donors. Based on this experience, blood services have the opportunity to expand their role and participate in public health surveillance and research. The aim of this report is to share available resources to assist blood services in this area. MATERIALS AND METHODS: The Surveillance, Risk Assessment and Policy (SRAP) Sub-group of the International Society of Blood Transfusion (ISBT) Transfusion Transmitted Infectious Diseases (TTID) Working Party developed a Public Health Research Toolkit to assist blood services and researchers interested in expanding their role in public health research. RESULTS: The ISBT Public Health Research Toolkit provides resources for what blood services can offer to public health, examples of donor research studies, the utility of donor data and website links to public health agencies. The toolkit includes a customizable template for those interested in establishing and managing a biobank. CONCLUSION: The ISBT Public Health Research Toolkit includes resources to increase the recognition of the role blood donors can play in public health and to help blood services gain commitment and funding from various agencies for new research and surveillance.

Evaluation of transfusion reactions in patients following transfusion of blood components containing antibodies to HLA class I - An attempt to prevent TRALI in patients.

In an attempt to mitigate transfusion-related acute lung injury (TRALI), the Oslo Blood Center screened 1369 thrombapheresis donors for human leucocyte antigen (HLA)-specific antibodies. Anti-HLA antibodies were found in 200 donors who were deferred from donation of plasma-rich products. In a retrospective study, 2562 transfusions of thrombocytes (both apheresis and whole blood-derived) from 150 of these donors were subject to a thorough look back-investigation. Reports of 14 transfusion reactions were identified, none of which were classified as TRALI. Our study supports previous data indicating that the risk of TRALI is low. The value of screening for anti-HLA antibodies and subsequent deferral of donors with high levels of such antibodies remains questionable.

Prevention of potential delayed hemolytic transfusion reaction in two sickle cell patients using intravenous immunoglobulins and steroids before and after red blood cell exchange with antigen positive units and review literature.

Emergent Red Blood Cell (RBC) exchange is indicated in sickle cell disease (SCD) patients with severe acute chest syndrome. However, fully matched RBC units may not be available for patients with multiple RBC antibodies. Intravenous immunoglobulin (IVIG) and steroids were reported for preventing potential delayed hemolytic transfusion reaction (HTR) in simple transfusion of antigen-positive RBCs. We investigated the efficacy and safety of IVIG and steroids in two SCD patients presented with acute chest syndrome receiving RBC exchange with multiple incompatible units. The first patient had multiple historical alloantibodies, including anti-Jsb, although none of them were reactive. IVIG (1 g/kg) was given before and after RBC exchange with methylprednisolone (500 mg IV) one hour before exchange. Her sickle hemoglobin (HbS) was reduced from 89.4% to 17.4% after the exchange with five Jsb-positive units. The patient improved clinically without acute or delayed hemolysis. The second patient had reactive anti-Jsb on two different admissions 18 months apart. Only one of the sixteen units used in the exchanges was Jsb negative. He received the same IVIG regimen during both admissions but 100 mg IV hydrocortisone instead of methylprednisolone. His HbS was reduced from 63.4% to 22.4% after the first exchange. Significant clinical improvements were achieved after both exchanges. No delayed HTR was observed. Our experience of these two patients suggested that IVIG and steroids may be used in preventing potential delayed HTR in some SCD patients with rare antibodies receiving large amounts of antigen-positive RBC products.

Insight into hazards and control of transfusion-transmitted infections in Egypt: A narrative review.

Blood transfusion is a critical life-saving medical intervention, but it carries the risk of transfusion-transmitted infections (TTIs) that can lead to serious consequences. TTIs include viral, bacterial, parasitic, and prion infections, transmitted through asymptomatic donor blood, contamination of stored blood products, or transfusion-related immunosuppression. Recognized global agents posing challenges to blood safety include human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV), Syphilis, etc. Emerging pathogens like SARS-CoV-2, hepatitis E, and others present additional risks. The residual risk of TTIs, representing the likelihood of infected donations passing screening tests, varies globally. High-income countries generally show lower prevalence rates than low-income countries. In Egypt, the estimated prevalence rates for HIV, HBV, HCV, and syphilis markers among the donors are 0.23 %, 0.76 %, 2.33 %, and 0.24 %, respectively. In Egypt, specific residual risk estimates are scarce, but prevalence rates for key infections highlight existing challenges. The World Health Organization promotes a global blood safety strategy, advocating for national blood systems, voluntary non-remunerated donors, and quality-assured testing. Despite these measures, the establishment of a haemovigilance system which is critical for monitoring and preventing adverse events, including TTIs, is reported as lacking in Egypt. This highlights the importance of comprehensive surveillance and safety measures in the blood donation process to ensure universal access to safe blood. Primary health care can play a pivotal role in preventing TTIs.

Longitudinal analysis of annual national hemovigilance data to assess pathogen reduced platelet transfusion trends during conversion to routine universal clinical use and 7-day storage.

BACKGROUND: France converted to universal pathogen reduced (PR; amotosalen/UVA) platelets in 2017 and extended platelet component (PC) shelf-life from 5- to 7-days in 2018 and 2019. Annual national hemovigilance (HV) reports characterized longitudinal PC utilization and safety over 11 years, including several years prior to PR adoption as the national standard of care. METHODS: Data were extracted from published annual HV reports. Apheresis and pooled buffy coat [BC] PC use was compared. Transfusion reactions (TRs) were stratified by type, severity, and causality. Trends were assessed for three periods: Baseline (2010-14; ~7% PR), Period 1 ([P1] 2015-17; 8%-21% PR), and Period 2 ([P2] 2018-20; 100% PR). RESULTS: PC use increased by 19.1% between 2010 and 2020. Pooled BC PC production increased from 38.8% to 68.2% of total PCs. Annual changes in PCs issued averaged 2.4% per year at baseline, -0.02% (P1) and 2.8% (P2). The increase in P2 coincided with a reduction in the target platelet dose and extension to 7-day storage. Allergic reactions, alloimmunization, febrile non-hemolytic TRs, immunologic incompatibility, and ineffective transfusions accounted for >90% of TRs. Overall, TR incidence per 100,000 PCs issued declined from 527.9 (2010) to 345.7 (2020). Severe TR rates declined 34.8% between P1-P2. Forty-six transfusion-transmitted bacterial infections (TTBI) were associated with conventional PCs during baseline and P1. No TTBI were associated with amotosalen/UVA PCs. Infections with Hepatitis E (HEV) a non-enveloped virus resistant to PR, were reported in all periods. DISCUSSION: Longitudinal HV analysis demonstrated stable PC utilization trends with reduced patient risk during conversion to universal 7-day amotosalen/UVA PCs.

Do Children With an Allergic Transfusion Reaction Require Premedication For All Blood Products?

BACKGROUND: Children with a history of allergic transfusion reactions (ATRs) receive antihistamine premedication with or without hydrocortisone to prevent subsequent reactions. We aim to examine the frequency of developing ATRs to subsequent different blood product type transfusions. METHODS: A retrospective chart review of children who received blood product transfusions (packed red blood cells, platelets, frozen plasma, intravenous immunoglobin, albumin, and cryoprecipitate) and developed ATRs. Cases were identified through Transfusion Transmitted Injuries Surveillance System- Ontario database with a complementary chart review. Demographics and subsequent transfusions records were described. RESULTS: During this period, 35,925 blood products were transfused to 4153 patients. Thirty-eight ATRs were reported in 30 patients. All ATRs were minor except 1 anaphylaxis to albumin transfusion. Seven patients (23%) developed multiple ATRs, and all of them were of the same blood product type. A total of 60 subsequent different blood product types were transfused to the 7 patients who had multiple ATRs; none of those transfusions caused ATR. CONCLUSION: In children with a history of ATR, developing a reaction to a different blood product type is rare. Hence, premedicating those transfusions is not warranted.

Preventing transfusion-associated circulatory overload in acute care settings.

ABSTRACT: Transfusion-associated circulatory overload (TACO) is a potentially life-threatening complication that can occur with the transfusion of any blood component, and accounts for up to 24% of transfusion-associated patient fatalities. This article discusses how to develop evidence-based continuing education and guideline recommendations that will increase nursing staff awareness of TACO and guide nurses in prevention and prompt intervention.

Mitigating the risk of transfusion-transmitted infections with vector-borne agents solely by means of pathogen reduction.

BACKGROUND: This study evaluated whether pathogen reduction technology (PRT) in plasma and platelets using amotosalen/ultraviolet A light (A/UVA) or in red blood cells using amustaline/glutathione (S-303/GSH) may be used as the sole mitigation strategy preventing transfusion-transmitted West Nile (WNV), dengue (DENV), Zika (ZIKV), and chikungunya (CHIKV) viral, and Babesia microti, Trypanosoma cruzi, and Plasmodium parasitic infections. METHODS: Antibody (Ab) status and pathogen loads (copies/mL) were obtained for donations from US blood donors testing nucleic acid (NAT)-positive for WNV, DENV, ZIKV, CHIKV, and B. microti. Infectivity titers derived from pathogen loads were compared to published PRT log10 reduction factors (LRF); LRFs were also reviewed for Plasmodium and T. cruzi. The potential positive impact on donor retention following removal of deferrals from required questioning and testing for WNV, Babesia, Plasmodium, and T. cruzi was estimated for American Red Cross (ARC) donors. RESULTS: A/UVA and S-303/GSH reduced infectivity to levels in accordance with those recognized by FDA as suitable to replace testing for all agents evaluated. If PRT replaced deferrals resulting from health history questions and/or NAT for WNV, Babesia, Plasmodium, and T. cruzi, 27,758 ARC donors could be retained allowing approximately 50,000 additional donations/year based on 1.79 donations/donor for calendar year 2019 (extrapolated to an estimated 125,000 additional donations nationally). CONCLUSION: Pathogen loads in donations from US blood donors demonstrated that robust PRT may provide an opportunity to replace deferrals associated with donor questioning and NAT for vector-borne agents allowing for significant donor retention and likely increased blood availability.

Estimating the risks of prehospital transfusion of D-positive whole blood to trauma patients who are bleeding in England.

BACKGROUND AND OBJECTIVES: D-negative red cells are transfused to D-negative females of childbearing potential (CBP) to prevent haemolytic disease of the foetus and newborn (HDFN). Transfusion of low-titre group O whole blood (LTOWB) prehospital is gaining interest, to potentially improve clinical outcomes and for logistical benefits compared to standard of care. Enhanced donor selection requirements and reduced shelf-life of LTOWB compared to red cells makes the provision of this product challenging. MATERIALS AND METHODS: A universal policy change to the use of D-positive LTOWB across England was modelled in terms of risk of three specific harms occurring: risk of haemolytic transfusion reaction now or in the future, and the risk of HDFN in future pregnancies for all recipients or D-negative females of CBP. RESULTS: The risk of any of the three harms occurring for all recipients was 1:14 × 103 transfusions (credibility interval [CI] 56 × 102 -42 × 103 ) while for females of CBP it was 1:520 transfusions (CI 250-1700). The latter was dominated by HDFN risk, which would be expected to occur once every 5.7 years (CI 2.6-22.5). We estimated that a survival benefit of ≥1% using LTOWB would result in more life-years gained than lost if D-positive units were transfused exclusively. These risks would be lower, if D-positive blood were only transfused when D-negative units are unavailable. CONCLUSION: These data suggest that the risk of transfusing RhD-positive blood is low in the prehospital setting and must be balanced against its potential benefits.

Preventing alloimmunization using a new model for matching extensively typed red blood cells.

BACKGROUND AND OBJECTIVES: Alloimmunization is a well-known adverse event associated with red blood cell (RBC) transfusions, caused by phenotype incompatibilities between donor and patient RBCs that may lead to haemolytic transfusion reactions on subsequent transfusions. Alloimmunization can be prevented by transfusing fully matched RBC units. Advances in RBC genotyping render the extensive typing of both donors and patients affordable in the foreseeable future. However, the exponential increase in the variety of extensively typed RBCs asks for a software-driven selection to determine the 'best product for a given patient'. MATERIALS AND METHODS: We propose the MINimize Relative Alloimmunization Risks (MINRAR) model for matching extensively typed RBC units to extensively typed patients to minimize the risk of alloimmunization. The key idea behind this model is to use antigen immunogenicity to represent the clinical implication of a mismatch. Using simulations of non-elective transfusions in Caucasian donor and patient populations, the effect on the alloimmunization rate of the MINRAR model is compared with that of a baseline model that matches antigens A, B and RhD only. RESULTS: Our simulations show that with the MINRAR model, even for small inventories, the expected number of alloimmunizations can be reduced by 78.3% compared with a policy of only matching on antigens A, B and RhD. Furthermore, a reduction of 93.7% can be achieved when blood is issued from larger inventories. CONCLUSION: Despite an exponential increase in phenotype variety, matching of extensively typed RBCs can be effectively implemented using our MINRAR model, effectuating a substantial reduction in alloimmunization risk without introducing additional outdating or shortages.

Can transfusion-associated graft-versus-host disease (TA-GvHD) be prevented with leukoreduction alone?

Transfusion-associated graft-versus-host disease (TA-GvHD) is a rare but devastating disease with a very high mortality rate. Because of the high mortality and lack of effective treatments, the current state of the art is aimed at preventing TA-GvHD and this can be accomplished via irradiation of all cellular blood products (red blood cells, granulocytes, and platelets). However, given that TA-GvHD is driven by contaminating white blood cells, and the fact that the international transfusion community has largely embraced leukoreduction, this raises the question as to whether the quantitative reduction of leukocytes via filtration can itself prevent TA-GvHD, thus allowing hospitals to skip irradiation steps? In this paper, we review the medical literature to determine how many leukocytes are needed to be removed to prevent TA-GvHD, while providing brief overviews of this entity itself and current irradiation strategies.

Rationalised premedication practice for blood product transfusions: A single-centre quality initiative.

AIM: Blood and platelets are scarce resources that are an essential part of the supportive care for paediatric cancer patients. There are many inherent risks involved with transfusions including acute transfusion reactions (ATRs). Following an initial ATR, prophylactic medications are commonly given prior to subsequent transfusions. However, there are risks with medication administration as well as negative implications for the health system. Our aim was to prevent the automatic prescribing of premedications prior to blood and platelet transfusions for ATRs. We hypothesised this would not increase the risk of harm. METHODS: Our intervention was to eliminate automatic prescribing of intravenous corticosteroids and intravenous promethazine prior to a transfusion. This was approached through a behaviour change model and the implementation of recommended prescribing guidelines. Three Plan Do Study Act (PDSA) cycles refined the guidelines to align with clinicians' needs and build support through co-design. Data gathered on individual patients receiving transfusions and reaction rates during the trial were compared to international data. RESULTS: A total of 100 patients received a transfusion during the trial. Eleven patients either had a previous reaction or experienced their first reaction during this time. All patients followed the guidelines and had either no premedication or an oral antihistamine premedication. There were no breakthrough reactions using oral antihistamines. The overall reaction rate was 1.33%, which aligns with the reported data on ATRs internationally. CONCLUSION: A restricted prescribing approach to pharmaceutical cover prior to blood and platelet transfusions can be implemented effectively in a paediatric cancer population, without an increase in the risk of harm to the patients.

Guideline development for prevention of transfusion-associated graft-versus-host disease: reduction of indications for irradiated blood components after prestorage leukodepletion of blood components.

Transfusion-associated graft-versus-host disease (TA-GVHD) is a rare, commonly fatal complication of transfusion preventable by irradiation of blood units. The revision of the Dutch transfusion guideline addressed the question whether irradiation is still necessary if blood components are prestorage leukodepleted. We searched for published cases of TA-GVHD following transfusion of prestorage leukodepleted blood and through contacting haemovigilance systems. Six presumed cases were found, dating from 1998 to 2013. Four out of six patients had received one or more non-irradiated units despite recognised indications for irradiated blood components. In the countries providing information, over 50 million prestorage leukodepleted, non-irradiated, non-pathogen-reduced cellular components were transfused in a 10-year period. Potential benefits of lifting indications for irradiation were considered. These include reduced irradiation costs (€ 1.5 million annually in the Netherlands) and less donor exposure for neonates. Findings were presented in an invitational expert meeting. Recommendations linked to human leukocyte antigen similarity between donor and recipient or intra-uterine transfusion were left unchanged. Indications linked to long-lasting deep T-cell suppression were defined with durations of 6 or 12 months after end of treatment (e.g. autologous or allogeneic stem cell transplantation). Need for continued alertness to TA-GVHD and haemovigilance reporting of erroneous non-irradiated transfusions was emphasised.

Prevention of transfusion-transmitted infections.

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 agents (TTIs; hepatitis B virus [HBV], HIV, human T-cell lymphotropic virus types I and II, hepatitis C virus [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 United States, other high-income countries, and in high-incidence regions performing NAT. NAT screening has emerged as the preferred option for detection of newer TTIs including West Nile virus, Zika virus (ZIKV), and Babesia microti Although 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 (PRTs) 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 to 2017 ZIKV pandemic, a level of tolerable risk has yet to be defined in such a way that conflicting factors (eg, theoretical recipient risk, blood availability, cost, and commercial interests) can be reconciled. A unified approach to TTIs is needed, whereby novel tests and PRTs replace, rather than add to, existing interventions, thereby ameliorating cost and logistical burden to blood centers and hospitals.