Although the risk of acquiring transfusion transmitted viral infections is low due to donor testing, bacterial infections are still reported. Platelets are the most implicated product in bacterial contamination reports because they are stored at room temperature (20-24°C) and provide a favorable environment for bacterial growth. Sepsis occurs in about 1 in 25,000 platelet transfusions. It may be fatal in about 1 in 60,000 transfusions. Bacteria can be present in other components as well, such as Red Blood Cells, Cryoprecipitate (CRYO), and Fresh Frozen Plasma (FFP). Contamination in red cell components is rare with events occurring 1 in 250,000 transfusions. This low incidence is due to the refrigerated storage requirements for red cells at 1-6°C. Because FFP and CRYO are stored frozen, they are least likely to contain bacteria. Contamination usually occurs when these products are thawed in a water bath that contains bacteria.
Reactions range from minimal or no symptoms to fatal septic shock and death. Severity of the reaction depends on the bacterial species involved, the concentration and growth rate of the organisms, and the recipient's immune status. Septic reactions can present with a fever of higher than 38.5°C, rigors, and hypotension that begin during the transfusion. Patients may also experience nausea, vomiting, dyspnea, and diarrhea. Septic shock, oliguria, and disseminated intravascular coagulation (DIC) are also complications.