Plasma: Bacterial contamination

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Example(s) of typical appearance
Example(s) of a change in appearance

Bacterial contamination is the presence of bacteria in the blood. Blood should be free of bacteria. Blood is collected and manufactured under sterile conditions to maintain this aseptic state. Bacterially contaminated blood components should NOT be transfused and any components suspected of bacterial contamination based on a visual inspection should be reported to Canadian Blood Services using the feedback form on Contact the nearest distribution centre to report potential contamination and receive further instructions.

Possible (though rare) causes of bacterial contamination include the following: 

  • Donor with asymptomatic bacteremia (i.e., subclinical bacteria in blood)  
  • Inadequate cleansing of skin prior to venipuncture. (Please note: To minimize bacterial contamination, Canadian Blood Services uses a diversion pouch for the first portion of the blood collection. In addition to strict protocol on skin cleansing, the diversion pouch prevents the skin plug and skin bacteria from entering the main unit.)
  • Loss of sterility during component manufacturing or handling 

Visual appearance 

  • The presence of bacteria may produce gas resulting in unusual air bubbles. 
  • The presence of bacteria may activate clotting resulting in clots and fibrin strands. 
  • Cloudiness 
Two rows of five platelet units photographed side by side on a white surface.
Plasma units spiked with four bacterial species in a laboratory setting, photographed on Day 0 and Day 6 of cold storage. By Day 6, there were no observable changes in the plasma's appearance for any of the units spiked with bacteria, despite proliferation of two bacterial species (S. liquefaciens and P. fluorescens).