Canterbury DHB


Transfusion of Infected Blood

In This Section


Clinical Manifestations

Laboratory Diagnosis and Evaluation

Management and Prevention


Caused by infusion of blood or blood components which are bacterially contaminated due to bacteraemia in the donor, residual bacteria at the donor skin venepuncture site, or contamination in processing.

Platelets which are stored at room temperature are the blood component most likely to cause this type of reaction, with estimated risk of <1:10,000 units transfused overall, and are more associated with gram positive organisms. With RBCs, the risk is <1:250,000. Red cell transfusions are more likely to be contaminated by gram negative organisms that can survive the cold such as Yersinia and Pseudomonas. The exact incidence of this type of reaction is unknown and may be underestimated due to intercurrent illnesses within the recipient. This complication may affect autologous blood.

Clinical Manifestations

Laboratory Diagnosis and Evaluation

Perform standard laboratory investigations including culturing of the blood bag contents and the patient’s blood.

Gram stain of the blood bag contents will often reveal the presence of organisms. Organisms that have been found include:

Culture of blood should be performed at 4° C, 20° C, and 37° C.

Management and Prevention

This is an urgent situation and after the appropriate cultures have been obtained, IV antibiotics must be given if there is a clinical reason to suspect that infected blood has been transfused. Suitable empiric antibiotics to cover the likely bacteria are gentamicin 5-7 mg/kg IV stat and a broad-spectrum penicillin or cephalosporin.

Observation of the colour of the blood units should be made before transfusing blood, as contaminated blood may be darker and have a purplish discolouration.

About this Canterbury DHB document (5123):

Document Owner:

Steve Gibbons (see Who's Who)

Last Reviewed:

June 2019

Next Review:

June 2022


Note: Only the electronic version is controlled. Once printed, this is no longer a controlled document. Disclaimer

Topic Code: 5123