This is a companion article to the feature, “Blood Supply Now Safest Ever; Why?

According to FDA, there’s never been a safer time in history for transfusions. Released in September, the agency’s annual report of fatalities following blood collection and transfusion offers statistical evidence, including details on the causes of such fatalities for the 5-year period ending with fiscal year 2014.1

“In combined fiscal years 2010 through 2014, transfusion-related acute lung injury (TRALI) caused the highest number of reported fatalities (41%), followed by transfusion-associated circulatory overload (TACO) (22%) and hemolytic transfusion (HTR) reactions (total of 21%) due to non-ABO (14%) and ABO (7%) incompatibilities. Microbial infections (8%) and anaphylactic reactions (6%) each accounted for a relatively smaller number of reported fatalities.”

“While the number of fatalities attributed to TACO has varied, TACO was the second leading cause of transfusion-related fatalities over the 5-year reporting period,” the report says. Increasing interest in TACO is suggested by several studies currently under way, including a Phase 2 study, Severe Transfusion Reactions Including Pulmonary Edema (STRIPE), which will focus on strategies to prevent or reduce complications related to TACO.

The report also says the number of reported transfusion-related deaths attributable to anaphylaxis has remained small over the past 5 fiscal years. None of the 10 combined cases reported for FY2010 through FY2014 were decisively linked to IgA-deficient recipients; measured IgA levels conclusively ruled out eight cases and IgA was not measured in the remaining two cases. One of the four FY2010 cases involved a haptoglobin deficiency that was possibly implicated in the patient’s anaphylactic reaction. Of the two anaphylaxis cases in FY2014, testing ruled out haptoglobin deficiency in one case and in the other, neither haptoglobin nor IgA levels were determined for the recipient, the report says.

In FY2014 there was one reported fatality attributed to microbial infection, compared to five in FY2013, according to the report. The FY2014 fatality involved transfusion of a unit of pooled platelets, which was associated with sepsis due to Serratia marcescens.

There were no reported fatalities associated with transfusion of apheresis platelets reported in FY2014, as compared to three in FY2013, the report says. Over the 5-year reporting period, Babesia microti accounted for the greatest number of reported deaths due to microbial infection, while Staphylococcus aureus and Serratia marcescens accounted for equal numbers of fatalities (two each).

Four of the five infections associated with RBC transfusions were due to Babesia microti, and both of the Serratia marcescens infections were associated with transfusion of pooled platelets, the report says. The six deaths associated with transfusion of apheresis platelets were distributed evenly among six organisms (one each).

Recent articles provide additional information about transfusion-transmitted Babesia, and reflect continuing interest in bacterial contamination of platelet products. During the 5-year reporting period, six of the implicated bacteria associated with fatal microbial infections were facultative anaerobes, and two—Acinetobacter sp. and Pseudomonas fluorescens—were obligate aerobes, according to the report.


  1. Fatalities reported to FDA following blood collection and transfusion, annual summary for fiscal year 2014. Silver Spring, Md: Center for Biologics Evaluation and Research, FDA, 2015.