Transfusion‐transmitted CMV infection – current knowledge and future perspectives

Abstract

Transmission of human cytomegalovirus (CMV) via transfusion (TT-CMV) may still occur and remains a challenge in the treatment of immunocompromised CMV-seronegative patients, e.g. after stem cell transplantation, and for low birthweight infants. Measures to reduce the risk of TT-CMV have been evaluated in clinical studies, including leucocyte depletion of cellular blood products and/or the selection of CMV-IgG-negative donations. Studies in large blood donor cohorts indicate that donations from newly CMV-IgG-positive donors should bear the highest risk for transmitting CMV infections because they contain the highest levels of CMV-DNA, and early CMV antibodies cannot neutralise CMV. Based on this knowledge, rational strategies to reduce the residual risk of TT-CMV using leucoreduced blood products could be designed. However, there is a lack of evidence that CMV is still transmitted by transfusion of leucoreduced units. In low birthweight infants, most (if not all) CMV infections are caused by breast milk feeding or congenital transmission rather than by transfusion of leucoreduced blood products. For other patients at risk, no definitive data exist about the relative importance of alternative transmission routes of CMV compared to blood transfusion. As a result, only the conduction of well-designed studies addressing strategies to prevent TT-CMV and the thorough examination of presumed cases of TT-CMV will achieve guidance for the best transfusion regimen in patients at risk.

Epidemiology of Cytomegalovirus among pregnant women in Africa

“…CMV infection can be transmitted through transfusion of CMV-infected blood [65]. It is possible that some participants could have received CMVinfected transfused blood, perhaps due to lack of CMV screening in the blood products intended for transfusion.…”

Blood Transfusion-Associated Infections in the Twenty-First Century: New Challenges

“…Measures to reduce TT-CMV for high-risk groups include depletion of cellular blood products [leukoreduction] and selection of CMV-negative donations. Studies indicate that newly positive CMV-IgG donors pose the highest risk of transmitting CMV as their blood contains the highest levels of CMV DNA [45]. However, there is no scientific evidence according to a recent review that leukoreduction or any single strategy reduces the risk of TT-CMV infection in high-risk patients [46].…”

Blood transfusion safety in sub‐Saharan Africa: A literature review of changes and challenges in the 21st century

“…54 Although CMV risk is largely eliminated by leukoreduction, 55 neither leukoreduction of blood products nor CMV testing of blood donors is widely used in SSA. 56 Furthermore, CMV testing is impractical given the high seroprevalence in the general population. In a Nigerian blood donor study (n = 184), 97.4% of subjects were CMV immunoglobulin G positive and 52.6% were CMV immunoglobulin M positive.…”