Steven J. Drews

Background: Public access to up‐to‐date information on infectious diseases and outbreaks has grown rapidly with the advent of artificial intelligence platforms. While this information can improve patient care and support research, the sheer volume of available data coupled with the challenge of identifying misinformation and disinformation can be overwhelming. A key challenge is managing large information volumes and identifying early, subtle signals that may indicate risks or opportunities to prevent infection. The aim of this manuscript is to explain how a national blood operator identifies and evaluates subtle infectious disease signals generated by horizon scanning to proactively protect the blood supply, including biotherapy products. Methods: Horizon scanning protocols were developed to detect early signals of change (emerging/re‐emerging pathogens, geopolitical/environmental changes, scientific and technological advances, new therapies/treatments for infectious diseases, and blood operator transfusion medicine changes). Communication strategies were created to alert national and international transfusion medicine decision makers of blood safety‐related events. Results: Several key components of a horizon scanning approach are presented to illustrate how novel information can be identified, processed, and formulated into knowledge translation products. Efficient and cost‐effective approaches are presented to enable horizon scanning activities with limited resources and time commitments. Discussion: Horizon scanning is an efficient and necessary activity to safeguard the blood supply. Here we present a collaborative group‐based approach, which reduces operator bias and improves overall examination of multiple data sources. This approach does not require expensive technology, can focus on open‐source information, and engages new scientists in learning about infectious diseases.

Introduction: Transfusion‐transmitted malaria can occur when donors have unrecognized asymptomatic infection with submicroscopic parasitemia, highlighting the need to detect low‐level parasitemia in blood donor screening. However, these highly sensitive blood donor testing algorithms may refer donors to clinicians who use diagnostic algorithms with less analytical sensitivity. Here we describe the analytical sensitivity of a Health Canada (HC)/FDA approved blood donor screening test compared to commonly used diagnostic test algorithms. Study Design and Methods: The Roche cobas® Malaria NAT performance was assessed. A dilution series of known malaria‐positive clinical specimens was prepared ( Plasmodium falciparum , P. vivax , and P. ovale ) (1:10 ⁴ –10 ⁷ ). Percent parasitemia (%parasitemia) via microscopy of clinical samples was used to estimate the infected red blood cells (iRBCs/mL) assuming 5 × 10 ⁹ RBC/mL. Limit of detection (LoD) at 50% and 95% was calculated. LoDs were compared to currently used Canadian diagnostic methods. Results: Comparison of whole blood and base matrix LoD ₉₅ and LoD ₅₀ were within 1 log for detection of Plasmodium spp. Overall, Plasmodium spp. LoD ₅₀ was 13.3 iRBC/mL and 2.4 × 10 ⁻⁷ % parasitemia while LoD ₉₅ was 167.1 iRBC/mL and 2.8 × 10 ⁻⁶ % parasitemia. LoDs were on average >2 logs lower than other diagnostic tests employed in Canada. Conclusion: Blood operators using highly sensitive donor testing Plasmodium NATs should develop approaches to educate clinicians on characteristics of these tests, as analytical sensitivities may be more sensitive than current diagnostic testing algorithms. Key groups to engage for management of Plasmodium NAT‐positive donors include primary care practitioners, infectious diseases physicians, tropical/travel medicine experts, clinical microbiologists, and public health.

Background: Emerging and re‐emerging arboviral infections are a risk to blood safety. We conducted an international survey on how blood establishments respond to current and future arbovirus threats. Study Design and Methods: A questionnaire on arbovirus donor deferral strategies, pathogen reduction, and donation screening was distributed to members of the International Society of Blood Transfusion working party on transfusion‐transmitted infectious diseases. Data from 2024 were gathered and analyzed. Results: A total of 23 survey responses were received from 21 countries. This covered a population of 1.45 billion people and 29.9 million blood donations collected in 2024. All respondents applied travel‐based donor deferrals, whereas pathogen reduction, implemented by half of the respondents, was mostly applied for a selection of plasma and platelet donations. West Nile virus (WNV) was the only arbovirus blood donations were screened for by nine respondents from eight countries, with 256 donations confirmed as WNV RNA‐positive in 2024. No transfusion‐transmitted WNV infections were reported. Discussion: Blood safety measures remain limited and unevenly distributed globally, and in their present form, are unlikely to provide protection against the growing range of emerging arboviruses. Donor deferral may not always be a sustainable blood safety strategy alone for all blood operators, due to large‐scale outbreaks associated with these viruses. While pathogen reduction methodologies are being developed to be applied to all blood components, risk assessments for (re)‐emerging arboviruses, such as dengue, chikungunya, and Zika viruses, should be performed to determine if additional mitigation, such as blood donation screening, is warranted.

Highlights The study uses a simple decision tree approach to study how a parvovirus B19 (B19V) and hepatitis A virus (HAV) nucleic acid test (NAT) might be implemented to qualify plasma for fractionation. The study identifies caveats that other blood operators may need to consider when assessing whether to implement a B19V/HAV NAT assay.

Background: In 2022, Canadian Blood Services implemented a gender‐neutral sexual behavior‐based screening (SBBS) approach to donor deferral, replacing time‐based criteria targeting gay, bisexual and other men who have sex with men (gbMSM) and female partners of gbMSM. We assessed the impact of this policy change on human immunodeficiency virus (HIV), hepatitis C (HCV), and hepatitis B (HBV) prevalence, incidence, and residual risk. Study Design and Methods: We compared prevalence rates among first‐time donors, incidence rates, and residual risk for allogeneic donations made in the 3 years pre‐SBBS implementation and 3 years post‐SBBS implementation. Results: HIV and HBV prevalence remained steady while HCV prevalence increased among first‐time donors post SBSS‐implementation. Point estimates for incidence rates and residual risks decreased for each marker post‐implementation, but differences were not significant. Residual risks post‐implementation were 1 in 34.7 million for HIV, 1 in 64.1 million for HCV, and 1 in 3.1 million for HBV. Discussion: Residual risks of infection remain low following the implementation of a gender‐neutral sexual risk behavior‐based approach to donor deferral. This policy change has not negatively impacted the safety of the Canadian blood supply.

Background: Anaplasma phagocytophilum is a tick‐borne pathogen that causes anaplasmosis. Increased incidences of this disease in Canada and cases of transfusion‐transmitted anaplasmosis in the United States have been reported. Currently, there are no Health Canada licensed methodologies available for detection of A. phagocytophilum nucleic acids (NAs) in blood donors. Here we describe a method for NA extraction and detection of A. phagocytophilum in whole blood (WB) donor samples. Study Design and Methods: Plasmids carrying the A. phagocytophilum msp2 and gltA genes and genomic A. phagocytophilum DNA were used to spike WB (10 ² –10 ¹⁰ plasmid copies, and 3.35 × 10 ⁶ genome copies/1.1 mL of WB, respectively) which was added to proprietary WB collection tubes (RWBCT). The tubes were frozen at −20°C for ≥48 h followed by NA extraction and detection of the msp2 and gltA genes using SYBR green‐based qPCR. Unspiked WB and human glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) gene amplification were used as process controls. Specificity was assessed with plasmids containing gene fragments from Anaplasma marginale and Anaplasma platys . Assays were run in triplicates. Results: A. phagocytophilum msp2 and gltA were detected by qPCR in plasmid‐spiked WB at a concentration of 10 ³ copies/1.1 mL of WB; however, the gltA primer set yielded false positive results. Additionally, genomic A. phagocytophilum DNA was successfully detected in spiked WB using msp2 specific primers. Cross reaction with A. platys msp2 and A. marginale gltA was observed with the A. phagocytophilum primer sets. Conclusion: A simple, scalable in‐house protocol for NA extraction from RWBCT has been optimized to detect A. phagocytophilum in WB donor samples.

Background and Objectives: Malaria still poses a public health burden in India despite ongoing elimination efforts. Blood donor screening for malaria is mandated in India, yet data on transfusion‐transmitted malaria (TTM) are lacking. We sought to evaluate testing practices for malaria, associated rates of positivity in donors and reported cases of TTM in India. Materials and Methods: We conducted a cross‐sectional survey of blood collection facilities in India from May to September 2025. Facilities were recruited through professional networks and direct outreach; responses were de‐identified. Data were collected on screening practices, malaria endemicity, quality control measures and TTM cases from 2020 to 2024. Results: Among 262 facilities, 256 (97.7%) reported routine malaria screening of all donations, most commonly using antigen rapid diagnostic tests (RDTs) (228/256, 89.1%). From 2020 to 2024, facilities tested 9,275,688 donations, with 1231 confirmed positive donations (overall 13.27 per 100,000 units) and a rising annual positivity rate from 3.4 to 22.0 per 100,000 units. Only eight facilities (3.1%) reported TTM cases, and less than half of facilities (116/256, 45.3%) participated in external quality assessment (EQA) and/or performed lookback investigations (88/262, 33.6%). Conclusion: In this national survey sample in India, almost all facilities reported routine malaria screening of blood donations, mostly using RDT. The findings suggest that rates of donor positivity may have increased, yet TTM is under‐recognized and/or unreported. Strengthening EQA and haemovigilance, particularly in malaria endemic regions, is needed to safeguard the blood supply, particularly as India strives towards malaria elimination.

Background: Babesia is a parasite transmitted by the Ixodes tick and has the potential to be transfusion transmitted. Climate change and changing Ixodes tick distributions in Canada raised questions about the impact of Babesia on the blood supply. Following a risk‐based decision making (RBDM) process, Canadian Blood Services initiated a multi‐year Babesia nucleic acid test (NAT) surveillance program in 2024. The first year of the project focused on a region (Manitoba, Canada) previously determined by the RBDM analysis to be of highest risk for Babesia NAT‐positive donations. The aim of this study is to provide an update on this multi‐year surveillance project that will shape our understanding of Babesia epidemiology in multiple Canadian provinces. Study Design and Methods: From July 11, 2024 to November 9, 2024, samples were collected in Roche Whole Blood Collection tubes at all whole blood donation sites in Manitoba. Specimens underwent one‐time individual testing on the cobas Babesia NAT on the Roche cobas 6800 platform (Roche Diagnostics GmbH, Mannheim, Germany). Clinical cases of babesiosis were reviewed for the period 2013–2025. Results: Of the 13,608 (98%) whole blood donations tested by Babesia NAT, none were positive. Clinical case rates of babesiosis in Manitoba ranged from 0 to 0.13 per 100,000 population annually. Discussion: Changing climate and Ixodes tick distributions have led to concerns that the epidemiology of Babesia infection in Canadian blood donors is increasing. Babesia NAT on specimens from an elevated‐risk area for Babesia infection in Canada did not identify Babesia ‐positive blood donors.

Background and Objectives: Canadian Blood Services implemented a re‐entry programme in 2014. Donors deferred because of false‐reactive or indeterminate screening tests can provide a specimen for re‐entry testing 6 months after their initial test, and resume donating if they test negative for all infectious markers. We evaluated the impact of the programme on donor return and retention, and assessed factors associated with reactive results upon re‐entry testing. Materials and Methods: Using extracted data from our donor database, we followed up donors who tested false‐reactive for hepatitis B virus (HBV), human immunodeficiency virus (HIV) and hepatitis C virus (HCV), from the implementation of the programme on 3 February 2014 until 30 June 2025 ( n = 8094). We characterized the donors reaching each step of the programme by sex, age, donation status and infection marker. We employed logistic regression to identify important predictors of obtaining reactive results upon re‐entry testing. Results: Overall, 17.3% of donors eligible for re‐entry testing successfully returned and donated. Re‐entry testing participation rates were 35.5%, with repeat and older donors more likely to participate. Among re‐entry tested donors, 59.2% tested negative. Most donors continued to donate for multiple years upon re‐entry. Upon return, 13.1% tested false reactive on a subsequent donation. False‐reactives upon re‐entry testing were more likely for first‐time donors and less likely when a different assay was employed than for the initially false‐reactive. Conclusion: The implementation of a donor re‐entry programme has resulted in donor retention and increases in the blood supply. Sending reminder notifications to eligible donors could increase participation.