bacterial contaminations

Bacterial sepsis continues to occur at high frequency especially in neutropenic patients, passive hemovigilance fails to reliably detect such reactions and commonly used clinical diagnostic criteria are not useful for the recognition of transfusion reactions associated with exposure to bacterially contaminated platelets, these are some of the conclusions published by Hong et all in 2016.²

Can we consider transfusion-related sepsis a silent epidemic?³ In the below section we shine light on this question and aim to bring you up to date with the latest, most relative insights on the rate of bacterial contamination in platelet concentrates and why transfusion related sepsis remains often unnoticed and underreported. Furthermore: how does a clinician looks at this when he is treating a patients and does pathogen inactivation matters when he orders platelet concentrates? Finally we share some insights from the European Centre for Disease Prevention and Control (ECDC) on the prioritization of bacterial pathogens transmissible via blood and blood components⁴.

Bacterial contamination rate of platelet components

Ryan A. Metcalf | Medical Director, Blood Bank Assistant Professor; Inpatient Chief Value Officer; Department of Pathology | University of Utah and ARUP Laboratories

Multiple individual studies have reported bacterial contamination rates for both whole blood and apheresis platelet collections. Based on a systematic review of published data and meta-analysis best estimates of bacterial contamination rates were obtained for apheresis, platelet rich plasma and buffy coat collection methods. The impact of collection method, sample volume, positivity criteria, and study date on the bacterial contamination rate was determined. A second systematic review and meta-analysis evaluated risk associated with false negative primary culture results.

Why bacterial contamination remain undetected and underreported?

Richard Benjamin | Chief Medical Officer | Cerus Global Headquarters

Contaminated platelets are often transfused, yet septic reactions are reported infrequently. Are contaminated platelets that do not cause sepsis clinically relevant? Why do septic transfusion reactions often go unnoticed? What are the reasons that only a minority of suspected reactions reported by hospitals are confirmed and are reported in official hemovigilance reports?

Why clinicians care about bacteria?

Helmut Ostermann | Professor of Internal Medicine, Haematology and Oncology | LMU Klinikum, University of Munich

Haematology departments are major users of platelet concentrates and take many measures to prevent infections in e.g. leukemia patients. At the same time systematic review of published data and meta-analysis estimates the bacterial contamination rates to be ~1/900 platelet concentrates^5-6. In the European community a patient receive on average 6–7 platelet transfusions⁷, however highly immunocompromised allogeneic stem cell transplant patients which are particularly susceptible to infection may receive as many as 30 to 50 platelet transfusions³. How does a clinician look at this when he is treating a patient and does pathogen inactivation matters when he orders platelet concentrates?

Why blood donors with periodontitis represents a safety risk?

Christian Damgaard | Head of Section, Associate Professor Section for Oral Biology and Immunopathology, Department of Odontology, Faculty of Health and Medical Sciences | University of Copenhagen

In most countries periodontitis affects more than half of the population over the age of 50⁸. The hypothesis in this study is that blood from donors with periodontitis have a higher incidence of viable bacteria than blood from donors without periodontitis. The investigator further hypothesize that those viable bacteria identified by direct culture are missed by standard screening protocols for bacterial contamination of donor blood⁹. Discover their findings.

Which bacteria represents a threat for the blood supply?

Clinical relevant bacteria (ECDC)

The European Centre for Disease Prevention and Control (ECDC) organized an expert consultation, with the objective of developing a priority list of bacterial pathogens transmissible via substances of human origin (SoHO). Three transmission pathways, blood and blood components, tissues and cells, and organs, were considered in the ranking exercise. Discover the results for blood and blood components⁴.

United States Government Food & Drug Administration (FDA). Fatalities reported to FDA following blood collection and transfusion: Annual summary for FY 2017.
Hong H, Xiao W, Lazarus HM, Good CE, Maitta RW, Jacobs MR. Detection of septic transfusion reactions to platelet transfusions by active and passive surveillance. 2016;127(4):496-502.
Benjamin R.; Transfusion-related sepsis: a silent epidemic; Blood, 2016; Volume 127, Number 4
Domanovic D.; Prioritizing of bacterial infections transmitted through substances of human origin in Europe; Transfusion 2017;57;1311–1317
White K.; Bacterial contamination rate of platelet components by primary culture: a systematic review and meta-analysis; Transfusion 2020;60;986–996
Walker S.; Residual bacterial detection rates after primary culture as determined by secondary culture and rapid testing in platelet components: A systematic review and meta-analysis, Transfusion. 2020;60:2029–2037.
Summary of the 2020 annual reporting of serious adverse reactions and events for blood and blood components; European Commission, Directorate-general for health and food safety.
Eke PI, Thornton-Evans GO, Wei L, Borgnakke WS, et al. Periodontitis in US adults: National Health and Nutrition Examination Survey 2009-2014. J Am Dental Assoc 2018; 149: 576-88
Christian Damgaard, Susanne G. Sækmose, Martin Nilsson, Mogens Kilian: Periodontitis increases risk of viable bacteria in freshly drawn blood donations. Blood Transfus 2021; DOI: 10.2450/2021.0336-20
Summary of the 2011 - 2020 annual reporting of serious adverse reactions and events for blood and blood components; European Commission, Directorate-general for health and food safety.