Transfusion-Transmitted Infections (TTI) Reported to the National Healthcare Safety Network (NHSN) Hemovigilance Module (HM), 2010 – 2015

BACKGROUND: Transfusion-transmitted infections (TTI) are important complications which result in significant morbidity and mortality among patients receiving blood products. They can be prevented through infectious risk factor screening of blood donors and, for many infections, laboratory testing of donations, along with newer methods such as pathogen-reduction technology. While viral blood-borne pathogens including HIV are rarely transmitted, transfusion-transmitted bacterial and parasitic infections occur more commonly. The National Healthcare Safety Network Hemovigilance Module is a surveillance system operated by CDC which tracks transfusion-related adverse events, including TTI. U.S. healthcare facilities monitor transfusion recipients and report the occurrence of TTI to the module. We present a summary of TTIs reported to NHSN from 2010-2015.

METHODS:  Participating facilities report the total number of blood components transfused monthly and TTI reports which include description of the pathogen and clinical severity of the reaction. Our analysis included all complete reports from participating facilities between January 1, 2010 and November 30, 2015. Frequencies of TTIs associated with red blood cells (RBC), platelets (PLT), plasma, or cryoprecipitate that met definite or possible case definition criteria were calculated. These reactions were further classified by severity.  Rates of TTI per total 100,000 transfused units, and further stratified by component type (RBC, PLT, plasma, and cryoprecipitate) were calculated.

RESULTS: A total of 176 facilities were included and reported 5,451,712 transfused components during the study period. These included 3,099,913 RBC, 974,092 PLT, 947,579 plasma, and 430,128 cryoprecipitate units. Forty TTIs were reported that met the case definition criteria. Of these, 25 indicated a serious reaction (21 severe; 2 life-threatening; 2 death). The most frequently reported pathogens were Staphylococcus aureus (6) and Babesia spp. (10). Other reported clinically significant pathogens included Acinetobacter spp. (2), Escherichia coli (2), and hepatitis C (1).  There were no reported HIV transmissions. Among RBC TTIs, 10/19 were Babesia spp. and 16/22 TTIs linked to PLT were bacterial infections.  The overall TTI rate was 0.73 per 100,000 blood components. TTI rates per 100,000 RBCs and PLTs components were 0.61 and 2.16, respectively. No reported TTIs implicated plasma or cryoprecipitate units.

CONCLUSIONS: Although infrequent, TTI rates in U.S. hospitals suggest that interventions to prevent these reactions are important for patient safety. In addition to laboratory screening, implementation of pathogen-reduction technology may further reduce the occurrence of TTIs including Babesia spp. and bacterial infections. Participation in national hemovigilance is vital to understand the burden of TTI and implement interventions.