Secondary bacterial culture of platelets to mitigate transfusion-associated sepsis: A 3-year analysis at a large academic institution

Posttransfusion Sepsis Attributable to Bacterial Contamination in Platelet Collection Set Manufacturing Facility, United States

During May 2018‒December 2022, we reviewed transfusion-transmitted sepsis cases in the United States attributable to polymicrobial contaminated apheresis platelet components, including Acinetobacter calcoaceticus‒baumannii complex or Staphylococcus saprophyticus isolated from patients and components. Transfused platelet components underwent bacterial risk control strategies (primary culture, pathogen reduction or primary culture, and secondary rapid test) before transfusion. Environmental samples were collected from a platelet collection set manufacturing facility. Seven sepsis cases from 6 platelet donations from 6 different donors were identified in patients from 6 states; 3 patients died. Cultures identified Acinetobacter calcoaceticus‒baumannii complex in 6 patients and 6 transfused platelets, S. saprophyticus in 4 patients and 4 transfused platelets. Whole-genome sequencing showed environmental isolates from the manufacturer were closely related genetically to patient and platelet isolates, indicating the manufacturer was the most probable source of recurrent polymicrobial contamination. Clinicians should maintain awareness of possible transfusion-transmitted sepsis even when using bacterial risk control strategies.

Presence of Gram-negative bacteria and Staphylococcus aureus on the skin of blood donors in the Democratic Republic of the Congo

BACKGROUND

Skin bacteria may contaminate blood products but few data are available on sub-Saharan Africa (sSA). We assessed the presence of Gram-negative bacteria and Staphylococcus aureus on blood donor skin and evaluated skin antisepsis in the Democratic Republic of the Congo (DRC).

STUDY DESIGN AND METHODS

Among blood donors at the National Blood Transfusion Center (NBTC) and at a rural hospital, the antecubital fossa skin of the non-disinfected arm (not used for blood collection) was swabbed (25cm² surface) and cultured for total and Gram-negative bacterial counts. Bacteria were identified with MALDI-TOF and tested for antibiotic susceptibility by disk diffusion. For evaluation of the NBTC antisepsis procedure (i.e., ethanol 70%), the culture results of the disinfected arm (used for blood collection) were compared with those of the non-disinfected arm.

RESULTS

Median total bacterial counts on 161 studied non-disinfected arms were 1065 Colony-Forming Units (CFU) per 25 cm² , with 43.8% (70/160) of blood donors growing Gram-negative bacteria and 3.8% (6/159) Staphylococcus aureus (2/6 methicillin-resistant). Non-fermentative Gram-negative rods predominated (74/93 isolates, majority Pseudomonas spp., Acinetobacter spp.). Enterobacterales comprised 19/93 isolates (mostly Pantoea spp. and Enterobacter spp.), 5/19 were multidrug-resistant. In only two cases (1.9%, 2/108) the NBTC antisepsis procedure met the acceptance criterion of ≤2 CFU/25 cm² .

CONCLUSION

Skin bacterial counts and species among blood donors in DRC were similar to previously studied Caucasian populations, including cold-tolerating species and bacteria previously described in transfusion reactions. Prevention of contamination (e.g., antisepsis) needs further evaluation and customization to sSA.

Adverse transfusion reactions and what we can do

INTRODUCTION

Transfusions of blood and blood components have inherent risks and the ensuing adverse reactions. It is very important to understand the adverse reactions of blood transfusion comprehensively for ensuring the safety of any future transfusions.

AREAS COVERED

According to the time of onset, adverse reactions of blood transfusion are divided into immediate and delayed transfusion reactions. In acute transfusion reactions, timely identification and immediate cessation of transfusion is critical. Vigilance is required to distinguish delayed responses or reactions that present non-specific signs and symptoms. In this review, we present the progress of mechanism, clinical characteristics and management of commonly encountered transfusion reactions.

EXPERT OPINION

The incidence of many transfusion-related adverse events is decreasing, but threats to transfusion safety are always emerging. It is particularly important for clinicians and blood transfusion staff to recognize the causes, symptoms and treatment methods of adverse blood transfusion reactions to improve the safety. In the future, at-risk patients will be better identified and can benefit from more closely matched blood components.

The international experience of bacterial screen testing of platelet components with automated microbial detection systems: An update

In 2014, the bacterial subgroup of the Transfusion-Transmitted Infectious Diseases working party of ISBT published a review on the International Experience of Bacterial Screen Testing of Platelet Components (PCs) with an Automated Microbial Detection System. The purpose of this review, which is focused on publications on or after 2014, is to summarize recent experiences related to bacterial contamination of PCs and the use of an automated culture method to safeguard the blood supply. We first reviewed septic transfusion reactions after PC transfusion as reported in national haemovigilance systems along with a few reports from various countries on bacterial contamination of blood products. Next, we reviewed PC automated culture protocols employed by national blood services in the United Kingdom, Australia, Canada and large blood collection organization and hospital transfusion services in the United States. Then, we acknowledged the limitations of currently available culture methodologies in abating the risks of transfusion-transmitted bacterial infection, through a review of case reports. This review was neither meant to be critical of the literature reviewed nor meant to identify or recommend a best practice. We concluded that significant risk reduction can be achieved by one or a combination of more than one strategy. No one approach is feasible for all institutions worldwide. In selecting strategies, institutions should consider the possible impact on platelet components availability and entertain a risk-based decision-making approach that accounts for operational, logistical and financial factors.

Economic implications of FDA platelet bacterial guidance compliance options: Comparison of single-step strategies

BACKGROUND

Bloodborne pathogens pose a major safety risk in transfusion medicine. To mitigate the risk of bacterial contamination in platelet units, FDA issues updated guidance materials on various bacterial risk control strategies (BRCS). This analysis presents results of a budget impact model updated to include 5- and 7-day pathogen reduced (PR) and large volumed delayed sampling (LVDS) BRCS.

STUDY DESIGN AND METHODS

Model base-case parameter inputs were based on scientific literature, a survey distributed to 27 US hospitals, and transfusion experts' opinion. The outputs include hospital budget and shelf-life impacts for 5- and 7-day LVDS, and 5- and 7-day PR units under three different scenarios: (1) 100% LVDS, (2) 100% PR, and (3) mix of 50% LVDS - and 50% PR.

RESULTS

Total annual costs from the hospital perspective were highest for 100% LVDS platelets (US$2.325M) and lowest for 100% PR-7 units (US$2.170M). Net budget impact after offsetting annual costs by outpatient reimbursements was 5.5% lower for 5-day PR platelets as compared to 5-day LVDS (US$1.663 vs. US$1.760M). A mix of 7-day LVDS and 5-day PR platelets had net annual costs that were 1.3% lower than for 100% 7-day LVDS, but 1.3% higher than for 100% 5-day PR. 7-day PR platelets had the longest shelf life (4.63 days), while 5-day LVDS had the shortest (2.00 days).

DISCUSSION

The model identifies opportunities to minimize transfusion center costs for 5- and 7-day platelets. Budget impact models such as this are important for understanding the financial implications of evolving FDA guidance and new platelet technologies.

Acquired platelet storage container leaks and contamination with environmental bacteria: A preventable cause of bacterial sepsis

Background

Apheresis platelets (AP) may be contaminated by environmental bacteria via container defects acquired during processing, transport, storage, or transfusion, as highlighted by a recent series of septic reactions related to Acinetobacter spp. and other bacterial strains.

Study design and methods

The frequency and nature of acquired container defect reports to one manufacturer were evaluated from January 2019 to July 2020. The published incidence of contamination and sepsis due to environmental bacteria with culture screened AP in the United States was reviewed for the period of 2010–2019.

Results

Review of a manufacturers' records showed 23 US reports of leaks involving 24 containers attributed to postmanufacturing damage, at a rate of 44 per million distributed storage containers. Analysis of returned containers showed evidence of scratches, impressions, and/or piercings. Literature review of US hemovigilance data revealed that environmental bacteria comprised 7% of confirmed positive primary bacterial culture screens, were responsible for 14%–16% of reported septic, and 8 of 28 (29%) fatal reactions with bacterial‐culture screened AP. Sepsis cases have been reported with culture screened, point‐of‐issue (POI) tested, or pathogen‐reduced AP.

Discussion

Environmental contamination of AP is rare but can cause sepsis. Container damage provides a pathway for contamination after culture screening, POI bacteria testing, or pathogen reduction. Blood collectors and transfusion services should have procedures to ensure proper inspection, handling, storage, and transport of AP to avoid damage and should enhance efforts to detect defects prior to release and to eliminate bacteria from all contacting surfaces to minimize the risk of contamination.