What is the most common infectious adverse effect of blood transfusion?

The most common infectious adverse effect of blood transfusion is related to bacterial contamination. This occurs when blood products, particularly those stored at room temperature such as platelets, become contaminated with bacteria during collection, processing, or storage. The presence of bacteria in the blood can lead to serious complications, including septic reactions, which can manifest as fever, chills, and potentially more severe outcomes like shock.

The risk of bacterial contamination highlights the importance of proper handling and storage of blood components. In regions with robust blood bank practices, the incidence of this complication has been significantly reduced through rigorous screening and testing protocols. Nevertheless, it remains a critical concern in transfusion medicine due to the potentially rapid and severe consequences of a transfusion reaction stemming from contaminated products.

While other adverse effects like urticaria and hemolytic transfusion reactions do occur, they are typically related to immune responses rather than direct infections. Hepatitis, although a serious infection associated with past transfusion practices, has been significantly reduced in modern transfusion medicine due to screening measures for viral pathogens.