This section discusses possible infection from bacteria, viral and other causes.
Each are detailed below:
Infection - Bacterial
Usual cause
Bacteria may enter the blood during collection or preparation of components. Occasionally due to contamination of ports during thawing of frozen products in a waterbath. Both Gram positive and Gram negative organisms have been identified. Organisms capable of multiplying at low temperatures and those using citrate as a nutrient are most often associated with red cell contamination, especially Yersinia enterocolitica.
Incidence
For clinically apparent reactions, variously reported to be 1:100,000 for platelets (3), however, probably under-reported.
Main clinical features
Can be acute, severe and life-threatening. May be fatal. Onset of high fever, severe chills, hypotension or circulatory collapse during or soon after transfusion should suggest the possibility of bacterial contamination and/or endotoxin reaction. More common with platelets, previously frozen components thawed by immersion in a waterbath and red cell components stored for several weeks.
Investigation
Clinical assessment. Blood cultures from the patient. Culture and Gram stain of blood component.
Intervention
Stop transfusion immediately if suspected. Start broad-spectrum antibiotics once cultures have been taken, including staphylococcal cover. Cardiovascular support. Inform ARCBS.
Infection - Other
Usual cause
Infectious agents for which there are no routinely available tests to predict or prevent the disease. All potential blood donors are subjected to stringent screening procedures to minimise the risk that they will transmit infectious agents. Possible causes may include transfusion-transmitted malaria, Chagas Disease and Babesia. Risk of variant CJD is possible; not yet reported in Australia.
Incidence
Variable.
Main clinical features
Features of specific clinical infection.
Investigation
Clinical assessment. Microbiological investigation.
Intervention
Treat specific diagnosis. Inform ARCBS
Infection - Viral
Usual cause
Transfusion transmitted viral infections, such as hepatitis and HIV which may occur due to window period transmissions.
Incidence
ARCBS estimates of residual risk of transfusion-transmitted infection are based on published models.
Main clinical features
Variable severity from asymptomatic to fatal. Features of specific clinical infection.
Investigation
Clinical assessment. Liver function tests. Specific testing for viral markers.
Intervention
Treatment for specific diagnosis, if available. Reduction in the risk of CMV transmission by CMV seronegative or leucocyte depleted blood components. Inform ARCBS.