Transfusion Transmitted Injuries Surveillance System (TTISS): Executive summary for 2018–2022 and 2020–2024 reports

On this page

Overview

The Transfusion Transmitted Injuries Surveillance System (TTISS) summary report, published by the Public Health Agency of Canada (PHAC), presents national data on transfusion-related adverse reactions reported by Canadian hospitals participating in the TTISS network. The following summarizes the findings of TTISS' 2018–2022 and 2020–2024 reports.

PHAC established TTISS to collect and analyze non-nominal data on adverse reactions associated with blood transfusions. Hospitals that provide transfusion services across Canada voluntarily contribute data through their respective provincial and territorial (P/T) surveillance programs.

In collaboration with P/T partners, PHAC is responsible for collecting, managing, and analyzing TTISS data and producing surveillance reports. The overarching goal of TTISS is to enhance transfusion and patient safety in Canada by supporting evidence-based public health decision-making.

Key findings

Since its inception in 2001, TTISS has monitored adverse transfusion reactions (ATRs) related to the administration of blood components and plasma derivatives. By 2007, all provinces and territories—except Nunavut—were contributing data. Currently, the TTISS network captures more than 95% of transfusion activities across Canada.

Below are the key findings from each report.

Adverse transfusion reactions
Category 2018–2022 2020–2024
Total ATRs 4,308 4,073
Percentage of ATRs associated with blood components 64.1% (2,763) 66.2% (2,695)
Percentage of ATRs linked to plasma derivatives 35.9% (1,545) 33.8% (1,378)
Most commonly reported adverse transfusion reactions
Percentage of ATRs representing: 2018–2022 2020–2024
Transfusion-associated circulatory overload (TACO) for blood components 43.7% (1,208) 44.7% (1,204)
Intravenous immune globulin headache/hemolysis (IVIG-HD) for plasma derivatives 37.2% (575) 35.8% (492)
Imputability of reaction reactions
Likelihood that the reaction was caused by transfusion 2018–2022 2020–2024
Definitely related 10.1% 10.2%
Probably or possibly related 89.9% 89.8%
Reactions categorized by severity
Severity of ATRs 2018–2022 2020–2024
Non-severe 68.9% 70.5%
Severe 24.3% 23.1%
Life-threatening 5.3% 5.2%
Outcomes of adverse transfusion reactions
ATR outcomes 2018–2022 2020–2024
Minimal or no harm 90.5% 91.6%
Major or long-term effects 3.3% 3.0%
Death 1.8% 1.6%
Could not be determined 4.4% 3.8%

There were 79 deaths reported during 2018–2022, and 66 deaths during the 2020–2024 period.

Deaths related to transfusions
Possibility for deaths 2018–2022 2020–2024
Possibly transfusion-related (definite, probable, or possible imputability) 58.2% (46 deaths) 65.2% (43 deaths)
Not transfusion-related (doubtful, ruled out, or undetermined). 41.8% (33 deaths) 34.8% (23 deaths)

The leading causes of transfusion-related deaths were TACO and transfusion-related acute lung injury (TRALI), and included transfusion-associated dyspnea (TAD) for the 2020-2024 period.

Most deaths occurred among older patients (median age: 72 years for 2018–2022 and 73 years for 2020–2024), suggesting that comorbidities may have contributed to these outcomes. Further research is recommended to better understand the relationship between transfusion events, patient age, and mortality.

Full reports available

The full reports are available on the Government of Canada's publications website and can be searched by year.

Transfusion transmitted injuries surveillance system reports

Page details

2026-05-12