TACO Remains Most Common Transfusion Reaction in Canada’s National Surveillance Reports

A new summary report from the Public Health Agency of Canada’s (PHAC) Transfusion Transmitted Injuries Surveillance System (TTISS) shows that transfusion-associated circulatory overload (TACO) remained the most commonly reported adverse transfusion reaction (ATR) linked to blood components across both the 2018-22 and 2020-24 reporting periods.

The report summarizes national data on transfusion-related adverse reactions voluntarily submitted by Canadian hospitals participating in provincial and territorial TTISS surveillance programs. The TTISS network captures more than 95% of transfusion activities across Canada.

During the 2020-24 reporting period, TTISS recorded 4,073 ATRs, including 2,695 associated with blood components and 1,378 linked to plasma derivatives. TACO accounted for 44.7% of ATRs related to blood components, while intravenous immune globulin headache/hemolysis (IVIG-HD) represented 35.8% of plasma derivative reactions.

Between 2020 and 2024, 70.5% of reactions were classified as non-severe and 91.6% resulted in minimal or no harm to patients. Severe reactions accounted for 23.1% of ATRs during the reporting period, while 5.2% were considered life-threatening.

TTISS reported 66 deaths during the 2020-24 period, with 43 (65.2%) classified as definitely, probably or possibly related to transfusion. TACO and transfusion-related acute lung injury (TRALI) were the leading causes of transfusion-related deaths, with transfusion-associated dyspnea (TAD) also contributing.

The reports noted that most deaths occurred among older patients, with a median age of 73 years during the 2020-24 period, suggesting that underlying comorbidities may have contributed to outcomes. PHAC said additional research is needed to better understand the relationship between transfusion events, age and mortality.

This is the first report on blood safety in Canada published since the PHAC discontinued the country’s Blood Safety Contribution Program on March 31. A feature article in the May issue of AABB News explores the program’s impact and the future of hemovigilance in Canada.