Bacterial Sepsis

Description

Transfusion-associated bacterial sepsis is an infrequent but potentially fatal transfusion complication.

Bacterial contamination of donor blood may be present due to:

• inadequate aseptic technique during collection
• coring of the skin with the venipuncture needle
• transient asymptomatic donor bacteremia
• chronic low grade donor infection
• improper refrigeration of Red Blood Cells (RBCs) during storage or transportation
• contamination during the processing of pooled products
• contamination by infected water baths during thawing of frozen components
• defects in blood bags

The presence of toxins from gram-negative bacilli can cause severe endotoxin reactions, including shock, and deaths have been reported. Such reactions have been reported following transfusion of RBCs stored at 1- 6°C for several weeks, platelets stored at 20-24°C for up to five days, and frozen/thawed blood components whose ports may have been contaminated in a water bath.

Incidence

The reported rates of transfusion-associated bacterial sepsis vary widely depending on the surveillance system used. The true incidence is unknown and is likely under-reported. Platelets, which are stored at room temperature, present a greater risk than RBCs.

Estimated rates of bacterial contamination of RBCs and platelets resulting in bacterial infections in transfusion recipients are shown below:

Implicated Organisms 

Both gram-negative and gram-positive organisms have been implicated. There are many reports of gram-positive bacteria from normal skin flora and gram-negative bacteria from transient bacteremia. Gram-negative organisms are found more frequently in contaminated RBCs and are generally associated with more severe infections. Implicated organisms include but are not limited to: