New data available: Top 4 takeaways from our 2024 Surveillance Report

Canadian Blood Services’ 2024 Surveillance Report is now available on our professional education website, Profedu.ca. This report provides data from 2024 on the activities undertaken by members of our epidemiology and surveillance team that are essential for maintaining the safety of Canada’s Lifeline, including surveillance of transmissible blood-borne infection, infectious threats, and donor safety. 

What does the Surveillance Report tell us about Canada’s blood donors?  

The Surveillance Report provides key demographics about donors’ region, sex, and age. It also outlines characteristics about the donor base that demonstrate the need for ongoing recruitment efforts, including the proportion of repeat versus first time donors and donors from different ethnic backgrounds. For example, in 2024, the Surveillance Report’s data indicated that the majority of blood donations (including whole blood, platelet, and plasma) continue to come from repeat donors. While first time blood donors make up only around 22 per cent of whole blood donors overall, 39 per cent of those first-time donors are from a racialized group. This is related, in part, to increasing diversity in younger age groups and expanded self-identification options from 2023 onwards that donors can use to describe their ethnic backgrounds.

 This information about the demographics of the donor base is crucial, as Canadian Blood Services is recruiting towards its most ambitious goal ever: one million new donors in the next five years to meet the growing demand for blood and plasma products in Canada. 

Top 4 takeaways from the 2024 Surveillance Report 

1. Infection rates in donors remain low 

Infection rates for all infectious disease markers among both donors remains very low. Infectious disease markers that all donations are tested for are detailed in the report including human immunodeficiency virus (HIV), hepatitis C (HCV), hepatitis B (HBV), and syphilis. Additionally, results of testing for HTLV (human T-cell lymphotropic virus, a rare cause of leukemia) are available for all donations (except source plasma donations which do not require HTLV testing).  

While it is unlikely that syphilis could be transmitted by transfusion due to modern blood processing methods, syphilis cases have been increasing in the general population. In addition to being the lead author of the Surveillance Report, Dr. Sheila O’Brien’s 2023 publication in the peer-reviewed journal Transfusion provides information about syphilis surveillance. It was one of the most downloaded articles from the journal in 2023! 

The report also updates residual risk estimates—the chance that an infectious unit could enter inventory despite testing. These estimates, used by physicians to counsel patients around informed consent for blood transfusion, continue to show very low risk. 

2. Donors successfully re-entering after false-reactive infection test results 

Since 2014, donors who had previously received false-positive results for HIV, HBV, or HCV have been eligible to return to donate after additional testing. In 2023, this program expanded to include syphilis and HTLV. To date, these donor re-entry processes have supported nearly 4,000 donors to contribute over 40,000 donations, strengthening the active donor base while maintaining safety. 

3. Effective notification of confirmed infections 

Prior to donating blood, all donors are informed that their blood will be tested for markers of infectious disease, that any abnormal results will be communicated to them, and that public health authorities will be informed of confirmed positive test results, as required by law. All donations reactive to screening tests undergo confirmatory testing before the donors are notified. The impact of this notification process was evaluated in 2024 based on interviews with donors who had tested positive for HBV, HCV, HTLV and syphilis between 2006 and 2022. Interviews results report in the 2024 Surveillance Report show that donors understand their positive results and most seek medical care, reinforcing the effectiveness of this process. 

4. Sexual behaviour-based screening expands safe donation 

Since 2022, Canada has used sexual behaviour-based screening for all donors. This change removed questions about sexual orientation that previously prevented many sexually active gay, bisexual, queer, and other men who have sex with men, and some trans people, from donating blood. The 2024 Surveillance Report includes an analysis on the compliance of donors with the new screening questions. It demonstrates there has been no increase in HIV-positive donations following the change in eligibility criteria. 

Why surveillance matters 

For the blood system, surveillance is about more than testing; it includes horizon scanning to identify emerging threats and monitoring. The 2024 report demonstrates Canadian Blood Services’ commitment to a rigorous, transparent, and evolving blood safety system. 

Dr. Sheila O’Brien, Canadian Blood Services associate director of epidemiology and surveillance, emphasizes that "monitoring infections in our donors is fundamental to the safety of the blood supply. It allows us to see when trends may be changing and intervene early.” 

The full 2024 Surveillance Report can be accessed on Canadian Blood Services’ professional education website, profedu.ca. 

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Through discovery, development and applied research, Canadian Blood Services drives world-class innovation in blood transfusion, cellular therapy and transplantation—bringing clarity and insight to an increasingly complex healthcare future. Our dedicated research team and extended network of partners engage in exploratory and applied research to create new knowledge, inform and enhance best practices, contribute to the development of new services and technologies, and build capacity through training and collaboration. Find out more about our research impact.   

The opinions reflected in this post are those of the author and do not necessarily reflect the opinions of Canadian Blood Services nor do they reflect the views of Health Canada or any other funding agency.