Strategies for the avoidance of bacterial contamination of blood components

Safety Analysis of Extended Platelet Shelf-Life with Large-Volume Delayed Sampling on BACT/ALERT® VIRTUO® in Australia

Transfusion-transmitted bacterial infection (TTBI) is the leading cause of transfusion-transmitted infections. Platelet components are more likely to be associated with bacterial contamination due to their storage requirements. Australian Red Cross Lifeblood introduced the bacterial contamination screening (BCS) of all platelet components in 2008. The process was recently updated with the use of BACT/ALERT® VIRTUO®, a large-volume delayed sampling (LVDS) protocol and extending platelet shelf-life to seven days. This article describes the results from the routine BCS of platelet components in Australia. Use of VIRTUO has resulted in lower false-positive rates, reducing wastage and improving platelet inventory. Our findings show that the combination of LVDS and VIRTUO improves the safety of platelet transfusions through earlier time to detection, especially for pathogenic bacterial species. Pathogenic bacteria grew within 24 h of incubation with a clear delineation between pathogenic and non-pathogenic species. The data show this protocol is very safe, with no TTBI cases during this time. There were no TTBI reports in recipients of platelet components that subsequently had a positive culture with Cutibacterium species, probably due to the low pathogenic potential of these organisms and slow replication in aerobic platelet bags. We conclude there is no advantage in incubating culture bottles beyond five days.

Recent Advances in Hemostasis at the Nanoscale

Rapid and effective hemostatic materials have received wide attention not only in the battlefield but also in hospitals and clinics. Traditional hemostasis relies on materials with little designability which has many limitations. Nanohemostasis has been proposed since the use of peptides in hemostasis. Nanomaterials exhibit excellent adhesion, versatility, and designability compared to traditional materials, laying a good foundation for future hemostatic materials. This review first summarizes current hemostatic methods and materials, and then introduces several cutting-edge designs and applications of nanohemostatic materials such as polypeptide assembly, electrospinning of cyanoacrylate, and nanochitosan. Particularly, their advantages and working mechanisms are introduced. Finally, the challenges and prospects of nanohemostasis are discussed.

Incidence of elevated procalcitonin and presepsin levels after severe trauma: a pilot cohort study

Procalcitonin (PCT) and presepsin (PSEP) are useful biomarkers for diagnosing sepsis; however, elevated PCT and PSEP levels may be observed in conditions other than sepsis. We hypothesised that PCT and PSEP levels could increase after severe traumatic injuries. Trauma patients with an Injury Severity Score of ≥16 from October 2013 to September 2015 were enrolled in our study. We examined PCT and PSEP levels and their positive rates on days 0 and 1. PCT and PSEP levels on days 0 and 1 were compared. Risk factors for increasing sepsis biomarker levels were identified by multivariate logistic regression analyses. In this study, 75 patients were included. PCT levels on days 0 and 1 were 0.1±0.4 and 1.8±6.3 ng/ml, respectively (P=0.02). PSEP levels on days 0 and 1 were 221±261 and 222±207 pg/ml, respectively (P=0.98). As per multivariate logistic regression analyses, packed red blood cell (PRBC) transfusion was the only independent risk factor for higher PCT levels on day 1 (P=0.04). Using PCT to diagnose sepsis in trauma patients on day 1 requires caution. PRBC transfusion was found to be a risk factor for increasing PCT levels. On the other hand, PSEP levels were not affected by trauma during the early phases.

Variability in the Use of Platelet Transfusion in Patients with Intracerebral Hemorrhage: Observations from the Ethnic/Racial Variations of Intracerebral Hemorrhage Study

BACKGROUND

We examined platelet transfusion (PTx) in the Ethnic/Racial Variations of Intracerebral Hemorrhage (ERICH) study, hypothesizing that rates of PTx would vary among hospitals and depend on whether patients were on an antiplatelet therapy or underwent intracerebral hemorrhage (ICH) surgical treatment.

METHODS

The ERICH study is a prospective observational study evaluating risk factors for ICH among whites, blacks, and Hispanics. We identified factors associated with PTx, examined practice patterns of PTx across the United States, and explored the association of PTx with mortality and poor outcome (modified Rankin Scale score 4-6).

RESULTS

Nineteen centers enrolled 2572 ICH cases; 11.7% received PTx. Factors significantly associated with PTx were antiplatelet use before onset (odds ratio [OR], 5.02; 95% confidence interval [CI], 3.81-6.61, P < .0001), thrombocytopenia (OR, 13.53; 95% CI, 8.43-21.72, P < .0001), and ventriculostomy placement (OR, 1.85; 95% CI, 1.36-2.52, P < .0001). Blacks were less likely (OR, .57; 95% CI, .41-0.80) to receive PTx. Among patients who received PTx, 42.4% were not on an antiplatelet therapy before onset. Twenty-three percent of patients on antiplatelet therapy received PTx, but percentages varied from 0% to 71% across centers. There was no difference in mortality or poor outcome at 3 months between patients receiving PTx and those who did not.

CONCLUSIONS

The frequency of PTx for ICH varies across academic centers. Thrombocytopenia, antiplatelet use, vascular risk factors, and ventriculostomy placement were associated with PTx. PTx was not associated with improved outcomes. We anticipate reduced PTx use over time given recent clinical trial data suggesting its use could be harmful; however, the issue of whether surgical management warrants PTx remains.

Stored Canine Whole Blood Units: What is the Real Risk of Bacterial Contamination?

Background

Bacterial contamination of whole blood (WB) units can result in transfusion‐transmitted infection, but the extent of the risk has not been established and may be underestimated in veterinary medicine.

Objectives

To detect, quantify, and identify bacterial microorganisms in 49 canine WB units during their shelf life.

Animals

Forty‐nine healthy adult dogs.

Methods

Forty‐nine WB units were included in the study. Immediately after collection, 8 sterile samples from the tube segment line of each unit were aseptically collected and tested for bacterial contamination on days 0, 1, 7, 14, 21, 28, 35, and 42 of storage. A qPCR assay was performed on days 0, 21, and 35 to identify and quantify any bacterial DNA.

Results

On bacterial culture, 47/49 blood units were negative at all time points tested, 1 unit was positive for Enterococcus spp. on days 0 and 1, and 1 was positive for Escherichia coli on day 35. On qPCR assay, 26 of 49 blood units were positive on at least 1 time point and the bacterial loads of the sequences detected (Propionobacterium spp., Corynebacterium spp., Caulobacter spp., Pseudomonas spp., Enterococcus spp., Serratia spp., and Leucobacter spp.) were <80 genome equivalents (GE)/μL.

Conclusions and Clinical Importance

Most of the organisms detected were common bacteria, not usually implicated in septic transfusion reactions. The very low number of GE detected constitutes an acceptable risk of bacterial contamination, indicating that WB units have a good sanitary shelf life during commercial storage.

Haemovigilance of reactions associated with red blood cell transfusion: comparison across 17 Countries

BACKGROUND AND OBJECTIVES

The recent establishment of the National Healthcare Safety Network Hemovigilance Module in the United States affords an opportunity to compare results with those of other developed nations.

MATERIALS AND METHODS

Using data from national haemovigilance systems, reactions associated with red blood cell (RBC) transfusion and residual risks of transfusion-transmitted infectious diseases were assembled from 17 nations. Country-specific rates of adverse events were pooled using random-effects Poisson regression.

RESULTS

Febrile non-haemolytic and delayed serologic transfusion reactions were the most frequent adverse events reported after RBC transfusion, occurring in 26 patients per 100 000 RBC units and 25 patients per 100 000 RBC units administered, respectively. Rates of allergic, febrile non-haemolytic and delayed haemolytic transfusion reactions in the United States were significantly greater than the pooled rates from other countries. Frequencies of adverse events generated from the national haemovigilance programme in the United States were considerably lower than when obtained through active surveillance.

CONCLUSION

Haemovigilance reports of adverse events in the United States are comparable to, or greater than, reports from other developed countries. Rates generated from haemovigilance programmes are lower than those obtained through active surveillance. The lack of universal leucoreduction of RBC units may be a contributing factor to the higher rate of some adverse events in the United States.

Guidelines for the Prevention of Intravascular Catheter–Related Infections

Background:

Although many catheter-related blood-stream infections (CRBSIs) are preventable, measures to reduce these infections are not uniformly implemented.

Objective:

To update an existing evidenced-based guideline that promotes strategies to prevent CRBSIs.

Data Sources:

The MEDLINE database, conference proceedings, and bibliographies of review articles and book chapters were searched for relevant articles.

Studies Included:

Laboratory-based studies, controlled clinical trials, prospective interventional trials, and epidemiologic investigations.

Outcome Measures:

Reduction in CRBSI, catheter colonization, or catheter-related infection.

Synthesis:

The recommended preventive strategies with the strongest supportive evidence are education and training of healthcare providers who insert and maintain catheters; maximal sterile barrier precautions during central venous catheter insertion; use of a 2% chlorhexidine preparation for skin antisepsis; no routine replacement of central venous catheters for prevention of infection; and use of antiseptic/antibiotic-impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies (ie, education and training, maximal sterile barrier precautions, and 2% chlorhexidine for skin antisepsis).

Conclusion:

Successful implementation of these evidence-based interventions can reduce the risk for serious catheter-related infection.

Hemostatic strategies for traumatic and surgical bleeding

Wide interest in new hemostatic approaches has stemmed from unmet needs in the hospital and on the battlefield. Many current commercial hemostatic agents fail to fulfill the design requirements of safety, efficacy, cost, and storage. Academic focus has led to the improvement of existing strategies as well as new developments. This review will identify and discuss the three major classes of hemostatic approaches: biologically derived materials, synthetically derived materials, and intravenously administered hemostatic agents. The general class is first discussed, then specific approaches discussed in detail, including the hemostatic mechanisms and the advancement of the method. As hemostatic strategies evolve and synthetic-biologic interactions are more fully understood, current clinical methodologies will be replaced.

Effects of storage temperature on hematopoietic stability and microbial safety of BM aspirates

Bone marrow (BM) remains a common source for hematopoietic SCT. Due to the transcutaneous approach, contamination with skin bacteria is common. The delay between harvest and transfusion can be considerable, potentially allowing for bacterial proliferation. The optimal transportation temperature, specifically with respect to bacterial growth and consequences thereof for hematopoietic quality, remain undefined. For 72 h, 66 individual BM samples, non-spiked/spiked with different bacteria, stored at 20-24 °C room temperature (RT) or 3-5 °C (cold), were serially analyzed for hematopoietic quality and microbial burden. Under most conditions, hematopoietic quality of BM was equal or better at RT: Typical BM contaminants (P. acnes and S. epidermidis) and E. coli were killed or bacterial proliferation was arrested at RT; hematopoietic quality was not impacted by the contamination. However, several pathogenic bacteria not typically found in BM (S. aureus and K. pneumoniae) proliferated dramatically at RT and impaired hematopoietic quality. Bacterial proliferation was arrested in the cold. The overwhelming majority of BM samples, that is, those that are sterile or contaminated only with skin commensals, will benefit from transportation at RT. Those bacteria that proliferate and perturb hematopoietic quality are not typically found in BM. Our data support recommendations for RT transportation and storage of BM.

Optimization of microbial screening for cord blood

BACKGROUND

Collection and processing of cord blood (CB) is associated with significant risk of contamination; hence standards mandate microbial screening of the final product. The sensitivity of current methods to evaluate the microbial content of CB is unknown, given the small volume tested and reduced sensitivity of pediatric bottles. Hence, this study was undertaken to evaluate an optimal microbial screening method.

STUDY DESIGN AND METHODS

CB was collected using a closed system then spiked with organisms at 1 or 10 colony-forming units (CFUs)/mL. Samples were screened using culture bottles (BacT/ALERT, bioMérieux; and BACTEC, Becton Dickinson). Several methods were evaluated with different combinations of inoculated bottles (adult vs. pediatric), sample types (plasma discard, red blood cell [RBC] discard, or final product), and sample volumes.

RESULTS

Of 94 cord blood units (CBUs) spiked with organisms before screening, 81% tested positive for contamination overall. Screening of CB in pediatric bottles resulted in equivalent detection rates on the BacT/ALERT and BACTEC systems (33% at 1 CFU/mL and 73% at 10 CFUs/mL, respectively). However, the pediatric bottle screen only detected 15% of obligate anaerobes. A combined fraction method showed superior detection (71%) compared to the plasma fraction (27%) and resulted in optimal anaerobic detection.

CONCLUSIONS

This study demonstrates that the optimal microbial screening method for CB includes testing a combination of discard fractions (plasma and RBCs) in addition to final product using an automated culture system. Inoculating a small sample of final product in a pediatric bottle is suboptimal for microbial detection and may lead to distribution of contaminated CB for transplantation.

Preliminary evaluation of optical glucose sensing in red cell concentrations using near-infrared diffuse-reflectance spectroscopy

Bacterial contamination of blood products is one of the most frequent infectious complications of transfusion. Since glucose levels in blood supplies decrease as bacteria proliferate, it should be possible to detect the presence of bacterial contamination by measuring the glucose concentrations in the blood components. Hence this study is aimed to serve as a preliminary study for the nondestructive measurement of glucose level in transfusion blood. The glucose concentrations in red blood cell (RBC) samples were predicted using near-infrared diffuse-reflectance spectroscopy in the 1350 to 1850 nm wavelength region. Furthermore, the effects of donor, hematocrit level, and temperature variations among the RBC samples were observed. Results showed that the prediction performance of a dataset which contained samples that differed in all three parameters had a standard error of 29.3 mg/dL. Multiplicative scatter correction (MSC) preprocessing method was also found to be effective in minimizing the variations in scattering patterns created by various sample properties. The results suggest that the diffuse-reflectance spectroscopy may provide another avenue for the detection of bacterial contamination in red cell concentrations (RCC) products.

Red blood cell products: consideration of the discrepant temperature ranges permitted for storage versus transport

The focus of this study was to determine if there is significant data to prohibit short-term storage of red blood cells (RBCs; i.e., <24 hr) at 1 to 10°C rather than 1 to 6°C, which occurs not uncommonly when RBCs are stored in a cooler for a patient during surgery. This document will describe the evidence in the literature to date regarding the potential impact of having RBCs temporarily in the 1 to 10°C range versus in the 1 to 6°C range, if any, on key measures of the quality of RBC storage: potassium, adenosine triphosphate, 2,3-diphosphoglycerate, posttransfusion survival, and bacterial contamination.

Access technique and its problems in parenteral nutrition - Guidelines on Parenteral Nutrition, Chapter 9

Catheter type, access technique, and the catheter position should be selected considering to the anticipated duration of PN aiming at the lowest complication risks (infectious and non-infectious). Long-term (>7-10 days) parenteral nutrition (PN) requires central venous access whereas for PN <3 weeks percutaneously inserted catheters and for PN >3 weeks subcutaneous tunnelled catheters or port systems are appropriate. CVC (central venous catheter) should be flushed with isotonic NaCl solution before and after PN application and during CVC occlusions. Strict indications are required for central venous access placement and the catheter should be removed as soon as possible if not required any more. Blood samples should not to be taken from the CVC. If catheter infection is suspected, peripheral blood-culture samples and culture samples from each catheter lumen should be taken simultaneously. Removal of the CVC should be carried out immediately if there are pronounced signs of local infection at the insertion site and/or clinical suspicion of catheter-induced sepsis. In case PN is indicated for a short period (max. 7-10 days), a peripheral venous access can be used if no hyperosmolar solutions (>800 mosm/L) or solutions with a high titration acidity or alkalinity are used. A peripheral venous catheter (PVC) can remain in situ for as long as it is clinically required unless there are signs of inflammation at the insertion site.

Analysis of bacterial detection in whole blood-derived platelets by quantitative glucose testing at a university medical center

After the March 2004 implementation of American Association of Blood Banks standards regarding platelet bacterial detection, we began quantitative glucose screening of whole blood-derived platelets (WB-P). The glucose level was measured immediately before component release--often storage day 4 or 5--using the Glucometer SureStep Flexx Meter (LifeScan, Milpitas, CA), with a positive cutoff of less than 500 mg/dL; failing units were cultured and not transfused. During 29 months (March 1, 2004-July 31, 2006) 93,073 units of WB-P were tested. Initially, 929 units (0.998%) screened positively. Bacterial growth was culture-confirmed in 6 units, for a bacterial contamination incidence of 0.006% and a true-positive rate of 6.4/100,000. Three additional culture-confirmed contamination cases were detected in transfused units causing febrile nonhemolytic reactions, for a false-negative rate of 3.2/100,000. Our overall contamination prevalence was 9.6/100,000 units of platelets transfused, lower than ordinarily cited, and showed a false-negative rate remarkably congruent to that of culture: 3.2/100,000. A low-sensitivity screening test applied late in platelet shelf-life can be comparable to culture in preventing bacterial-related morbidity.

Microbiological risk assessment in stem cell manipulation

Cell therapy based on the use of human stem cells is more complicated than transfusion or organ transplantation because cells may undergo many additional manipulations due to different treatments for isolation, expansion, differentiation, and other types of biological changes. These manipulations require the approval of regulatory agencies (other than ethical) and the processes must be monitored with more tests than the ones applied for minimally manipulated cells. The clinical safety and efficacy of transplanted cells depend on several factors such as homologous or non-homologous sources, extent of manipulation, and culture conditions. Moreover, the kind of information needed to address these issues may differ depending on whether the cells are to be used for tissue reconstruction or repair, or to recover metabolic functions. Also anatomical site, functional integration as well as duration of therapy, are crucial points that indirectly can influence safety. Many important assays have been suggested for environmental monitoring as well as to standardize microbiological controls in stem cell banks to prevent contamination. In order to guarantee safety two main aspects must be considered: one is related to the source of cells (the donor) and the other is depending on cell collection and processing. In this review we critically analyze the steps of the processes (from collection to banking) and consider the main factors involved in the clinical research (continuously in evolution) by suggesting a standardized facsimile form to use in the laboratory for the assessment of the microbiological risk related to the cell manipulations.

Real-Time Polymerase Chain Reaction in Transfusion Medicine: Applications for Detection of Bacterial Contamination in Blood Products

Bacterial contamination of blood components, particularly of platelet concentrates (PCs), represents the greatest infectious risk in blood transfusion. Although the incidence of platelet bacterial contamination is approximately 1 per 2,000 U, the urgent need for a method for the routine screening of PCs to improve safety for patients had not been considered for a long time. Besides the culturing systems, which will remain the criterion standard, rapid methods for sterility screening will play a more important role in transfusion medicine in the future. In particular, nucleic acid amplification techniques (NATs) are powerful potential tools for bacterial screening assays. The combination of excellent sensitivity and specificity, reduced contamination risk, ease of performance, and speed has made real-time polymerase chain reaction (PCR) technology an appealing alternative to conventional culture-based testing methods. When using real-time PCR for the detection of bacterial contamination, several points have to be considered. The main focus is the choice of the target gene; the assay format; the nucleic acid extraction method, depending on the sample type; and the evaluation of an ideal sampling strategy. However, several factors such as the availability of bacterial-derived nucleic acid amplification reagents, the impracticability, and the cost have limited the use of NATs until now. Attempts to reduce the presence of contaminating nucleic acids from reagents in real-time PCR have been described, but none of these approaches have proven to be very effective or to lower the sensitivity of the assay. Recently, a number of broad-range NAT assays targeting the 16S ribosomal DNA or 23S ribosomal RNA for the detection of bacteria based on real-time technology have been reported. This review will give a short survey of current approaches to and the limitations of the application of real-time PCR for bacterial detection in blood components, with emphasis on the bacterial contamination of PCs.

Canadian experience with detection of bacterial contamination in apheresis platelets

BACKGROUND

In Canada, both blood suppliers, Héma-Québec (HQ) and Canadian Blood Services (CBS), implemented bacterial testing in apheresis platelets (PLTs) with an automated microbial detection system (BacT/ALERT, bioMérieux).

STUDY DESIGN AND METHODS

Validation of the BacT/ALERT Classic and 3D systems involved apheresis PLT spiking with different bacteria at concentrations of 10 and 10(2) colony-forming units per mL. As of February 2006, more than 95 percent of apheresis PLTs were screened for bacterial contamination at HQ and CBS. Between 3.5 and 10 mL of PLTs is inoculated into BacT/ALERT aerobic culture bottles followed by incubation for a maximum of 7 days.

RESULTS

During the validation studies, all bacteria were detected at all concentrations and volumes tested. Upon implementation of bacterial screening, the percentage of initial positive samples at CBS and HQ was 0.09 and 0.07 percent, respectively. The rate of indeterminate cultures was significantly higher at CBS than at HQ, whereas the rates for true-positive, false-positive, and false-negative results did not differ significantly. Six confirmed-positive cultures, including three coagulase-negative staphylococci and three Enterobacteriaceae species, were detected and PLT units contaminated with these bacteria were not transfused. The rate of true-positive cultures was significantly lower than that reported by other blood operators. Unfortunately, failed detection of two contaminated units resulted in septic transfusion reactions.

CONCLUSION

Bacterial screening of apheresis PLTs in Canada was successfully implemented, and transfusion of contaminated units was prevented. Rapid bacterial detection systems that could be used before transfusion, however, may further reduce the risk of transfusion reactions.

[New container of sample: role in the reduction of bacterial contamination of standard platelet units]

BACKGROUND

Bacterial contamination of unstable blood products constitutes today the most frequent infectious risk transmitted by blood transfusion. Platelet concentrates are often incrimineted. As responsible germs are in general of cutaneous origin, a sample procedure with diversion of the first 20 ml during blood donation is studied. The aim of this study is to evaluate the results of this technique on bacterial contamination rate of standard platelet units prepared at the regional blood transfusion center in Casablanca.

STUDY DESIGN AND METHODS

A comparative study of two types of sample pockets is made: 500 Standard Platelet concentrates (CPS) are prepared after collection using standard triple bags (Baxter) (group 1) and 560 pockets of CPS were prepared after collection using triple bags with Sample Diversion Pouch sampling system for elimination of the first 20 ml of donation (Macopharma and Terumo) (group 2). The skin was disinfected in two times with alcohol 70%. The bacteriological study was made in the two groups at the third day of conservation.

RESULTS

Six CPS of group 1 were contaminated, of which five were staphylococci coagulase negative and one bacillus sp. Six CPS of group 2 were contaminated, of which five were staphylococci coagulase negative and one staphylococcus aureus. The bacteria isolated were those of cutaneous flora at 100%. Diversion of first 20 ml of blood donation results in a 16.6% reduction in bacterial contamination of CPS (P>0.05).

CONCLUSION

The non-significant reduction in the prevalence of the bacterial infection of CP formulates the problem of the indication of the sampling devices with derivation of first 20 ml during blood collection.

Bacterial risk reduction by improved donor arm disinfection, diversion and bacterial screening

The Interventions of improved donor arm disinfection, diversion and bacterial screening have been implemented by blood services and shown to have substantial benefit. The major source of bacterial contamination is donor arm derived. Blood services are now introducing best practice donor arm disinfection techniques. Diversion has been shown to substantially reduce bacterial contamination in the order of 40-88%. Diversion, together with improved donor arm disinfection, has shown to improve the percentage of reduction in contamination from 47% to 77%. Residual contamination levels after the Introduction of diversion and improved donor arm disinfection may be in the order of 30-40%. Numerous countries have now implemented screen testing programmes for platelet concentrates, which are the major source of bacterial transfusion transmission. Pathogen reduction systems have been developed and are under development. At present, concerns remain with these systems regarding cost, process control, ability to inactivate high titres of viruses, killing of bacterial spores, product damage, genotoxicity and mutagenicity. The interventions of diversion, improved donor arm disinfection and bacterial screen testing are currently available, As such they can be implemented now to increase blood safety with no associated patient risk.

Infectious complications after cardiac surgery: lack of association with fresh frozen plasma or platelet transfusions

OBJECTIVE

The purpose of this study was to examine the effect of perioperative transfusion of platelets and fresh frozen plasma (FFP) on infection rates after cardiac surgery.

DESIGN

Retrospective study comparing infection rates after cardiac surgery among patients receiving combinations of packed red blood cells (PRBCs), platelets, and FFP.

SETTING

Tertiary care university teaching hospital.

PARTICIPANTS

All elective primary coronary artery bypass (CABG) surgery patients from July 1995 to January 1998 before introduction of leukocyte-reduced blood products.

INTERVENTIONS

Multivariate logistic and linear regression models were applied to identify clinical risk factors for postoperative infection and to determine the relationship between perioperative administration of PRBCs, platelets, and FFP with postoperative infection.

MEASUREMENTS AND MAIN RESULTS

Transfusion of PRBCs, diabetes, age, preoperative hematocrit, and the duration of cardiopulmonary bypass were significantly associated with postoperative infection; platelet or FFP transfusion added no additional risk to PRBC transfusion alone.

CONCLUSIONS

Infectious complications in a population of adult primary CABG surgery patients were not increased by transfusion of platelets or FFP. It is PRBC transfusion that confers an increased risk of postoperative infection in this population.

Fatal Yersinia enterocolitica biotype 4 serovar O:3 sepsis after red blood cell transfusion

BACKGROUND

Although posttransfusion bacterial sepsis is rare, this complication is associated with a high mortality rate.

CASE REPORT

A fatal case of septic shock was observed in a 71-year-old patient following transfusion of contaminated red blood cells (RBCs) for refractory anemia. Yersinia enterocolitica was isolated from the patient's blood sample and the transfused RBCs. Both strains were of bioserotype 4/O:3 and had the same NotI pulsotype. High titers of antibodies against Y. enterocolitica were detected in the donor's plasma sample 1 month after blood donation. The donor reported abdominal discomfort 3.5 months before blood collection but had no clinical signs of intestinal infection at the time of donation.

CONCLUSION

Y. enterocolitica has been identified with increased frequency as a causative agent of posttransfusion septic shock. This nationwide investigation of these cases led to an estimated incidence of one case per 6.5 million RBC units distributed in France. Although rare, this often fatal complication remains nonpreventable worldwide owing to the lack of practical means for screening RBCs before transfusion.

Febrile nonhemolytic transfusion reactions. Management by premedication and cost implications in adult patients

CONTEXT

Febrile nonhemolytic transfusion reactions (FNHTRs) cause unwelcome interruptions during the course of blood product transfusions and necessitate measures to verify the nature of the reaction and to exclude certain dangerous reactions, such as hemolytic and septic phenomena.

OBJECTIVE

To examine transfusion medicine data to determine the clinical implications of the routine administration of antipyretic medication to adult patients before transfusion for the prevention of FNHTRs.

DESIGN

A retrospective review was conducted of FNHTR data during 5 years (1998-2002), and a determination was made of the cost of a transfusion complicated by an FNHTR. In addition, a comparative cost analysis was performed using our data and published data on the incidence of FNHTRs. The clinical implications of medication with respect to possible drug-induced adverse effects were assessed, as well as the potential interference with diagnosing other forms of transfusion reactions and the mitigation of the clinical effect of an FNHTR.

RESULTS

For nearly 120,000 U of transfused blood components, approximately 80% of which were preceded by antipyretic medication during the study period, the overall incidence of FNHTR was found to be 0.09%. Furthermore, there was no evidence of antipyretic-associated complications, nor any evidence that antipyretics prevented the recognition of other more dangerous complications of transfusions.

CONCLUSION

Our findings indicate that this practice provides significant advantages to the recipient of a transfusion, but does not appear to yield significant cost benefits for the health care provider.

Transfusion-transmitted bacterial infection: risks, sources and interventions

Records of the transmission of bacterial infections by transfusion date back to the beginning of organized blood banking. Despite tremendous strides in preventing viral infection through careful donor screening and viral testing, there has been little improvement in reducing the risk of bacterial sepsis since the introduction of closed collection systems. Based on the French Haemovigilance study, the British Serious Hazards of Transmission (SHOT) study and fatality reports to the United States Food and Drug Administration, the risk of clinically apparent sepsis exceeds the risk of HIV, HBV, and HCV transmission. Sources of contamination include the skin, blood, disposables, and the environment. Potential interventions to reduce transfusion-associated bacterial sepsis include improvements to donor arm preparation, diversion of the first aliquot of whole blood, introduction of bacterial testing and/or implementation of pathogen reduction methods.

In vivo PLT increments after transfusions of WBC-reduced PLT concentrates stored for up to 7 days

BACKGROUND

Bacterial screening and improvement of storage conditions of leukoreduced PLT concentrates (LR-PCs) allows extension of their storage period from 5 to 7 days.

STUDY DESIGN AND METHODS

For in vitro studies, 40 LR-PCs made from five buffy coats and plasma were studied for 8 days. For in vivo studies, routinely produced LR-PCs stored for 2 to 7 days after blood collection were administered to clinically stable thrombocytopenic patients. CI1 h was calculated after 353 transfusions (67 patients), and CCI1 h, after 195 transfusions (55 patients), with pretransfusion PLT counts of not greater than 20 x 10(9) per mL.

RESULTS

Storage experiments showed that the pH of LR-PCs remained greater than 6.8 for 8 days, provided that the PLT concentration was less than 1.3 x 10(9) per mL. Routinely produced LR-PCs had a volume of 282 +/- 15 mL (n = 10,193) and contained 329 x 10(9)+/- 40 x 10(9) PLTs (n = 3467). For 7-day-old LR-PCs, 76 of 78 (97%) of the transfusions resulted in a CI1 h of at least 10 and 37 of 39 (95%) in a CCI1 h of at least 7.5, which indicated levels for successfulness. Mean +/- SE values of CI1 h and CCI1 h of 7-day-old LR-PCs were 28.7 +/- 2.3 (n = 78) and 19.0 +/- 2.0 (n = 39), respectively. No significant differences were observed between 5- and 7-day-old LR-PCs transfused with respect to CI1 h and CCI1 h values.

CONCLUSION

In vitro and in vivo studies showed that LR-PCs can be stored for up to 7 days with excellent clinical results, provided that they are routinely screened for bacterial contamination.

[Fever-shivers reaction and standard platelet concentrates transfusion: a prospective study]

Fever-shivers reaction (FSR) is the most frequent transfusion immediate incident related to platelet transfusions. The aim of our prospective study was to assess the frequency of the different immediate incidents, especially the frequency and the causes of the FSR, observed during the transfusion of standard platelet concentrates (SPC). For each FSR, analysis of causes included: a bacterial culture of the implicated SPC, a blood culture and HLA antibody screening (lymphocytotoxicity assay) among the patients. In the study period, 34 patients were followed during 74 transfusions. Ten immediate incidents were noted; FSR: N = 8, erythema-urticaria: N = 1 and nausea-vomit: N = 1. The FSR was observed in 6 patients who received 56 SPC. Analysis of causes of this reaction revealed that: HLA antibodies were present in one patient; bacterial contamination was not found neither among the patients nor in the implicated SPC, and the risk of the FSR occurrence rose with increased storage time of the SPC transfused. Indeed, a significant difference was noted between the mean age of the SPC implicated in the FSR and the mean age of those not implicated (P = 0,0028). In conclusion, the FSR is a frequent incident observed during SPC transfusions. In the majority of cases, the cause of this reaction was not identified. Further studies will be necessary to better understand the physiological mechanisms of the FSR.

Estimation of bacterial risk in extending the shelf life of PLT concentrates from 5 to 7 days

BACKGROUND

The use of bacterial culture to prevent bacterial contamination of blood components has renewed interest for extending the shelf life of PLT concentrates to 7 days after collection.

STUDY DESIGN AND METHODS

This study was therefore conducted to determine the residual risk of bacterial contamination in PLT concentrates at the end of 5 and 7 days after collection in a center where all PLT concentrates are routinely screened by taking samples on Day 2 for culture. PLT units with no growth after 48 hours were sampled a second time on Day 5 or Day 7 after collection, followed by inoculation into aerobic culture bottles. The inoculated bottles were then monitored for up to 7 days at 35 degrees C in an automatic monitoring and detection system.

RESULTS

During a 16-month study period, a total of 6020 PLT concentrates were tested 5 days (Group A, n=3010) and 7 days (Group B, n=3010) after collection. Four units in each group (0.133%) were found to be contaminated. In 6 units, bacteria were seen on direct Gram stain. In addition, 5 of the associated RBC units grew the same organisms on culture. The organisms include three coagulase-negative staphylococci and five Propionibacterium acnes. The positive rate of routine short-term bacterial culture was 0.035 percent during the same study period.

CONCLUSION

Despite routine short-term bacterial culture, a significant risk of bacterial contamination remains at 5 and 7 days after collection. For now, the shelf life of PLT concentrates should remain 5 days.

Risks associated with transfusion of cellular blood components in Canada

We provide a comprehensive review of risks associated with allogeneic red blood cell and platelet transfusions in Canada. The review focuses on clinically symptomatic noninfectious transfusion risks (acute and delayed hemolytic, febrile nonhemolytic [FNHTR], allergic, volume overload, transfusion-related acute lung injury, graft-versus-host disease, and posttransfusion purpura) and the risk of clinically significant disease from transfusion-transmitted infections. Data sources include information from Canadian Blood Services, Héma-Québec, Health Canada, and the Québec Hemovigilance System as well as published information from research studies and international hemovigilance systems. We estimate that in 2000 the aggregate risk of potentially severe reactions (excluding FNHTR and minor allergic reactions) was 43.2 per 100000 red cell units (95% confidence interval [CI]: 38.7-48.1), affecting 337 recipients, and 125.7 per 100000 platelet pools of 5 units (95% CI: 100.8-154.9), affecting 88 recipients. The most frequent potentially severe outcomes for red cell transfusion were hemolytic reactions and volume overload and for platelet transfusion were major allergic reactions and bacterial contamination. The current risk of human immunodeficiency virus and hepatitis C virus transmission is approximately 1 in 4 million and 1 in 3 million units, respectively. These estimates are useful for decisions concerning transfusion therapy, the informed consent process, and for evaluating efficacy of interventions to reduce risk.

Bacterial Contamination of Blood Components: Risks, Strategies, and Regulation

Bacterial contamination of transfusion products, especially platelets, is a longstanding problem that has been partially controlled through modern phlebotomy practices, refrigeration of red cells, freezing of plasma and improved materials for transfusion product collection and storage. Bacterial contamination of platelet products has been acknowledged as the most frequent infectious risk from transfusion occurring in approximately 1 of 2,000–3,000 whole-blood derived, random donor platelets, and apheresis-derived, single donor platelets. In the US, bacterial contamination is considered the second most common cause of death overall from transfusion (after clerical errors) with mortality rates ranging from 1:20,000 to 1:85,000 donor exposures. Estimates of severe morbidity and mortality range from 100 to 150 transfused individuals each year.

Concern over the magnitude and clinical relevance of this issue culminated in an open letter calling for the “blood collection community to immediately initiate a program for detecting the presence of bacteria in units of platelets.” Thereafter, the American Association of Blood Banks (AABB) proposed new standards to help mitigate transfusion of units that were contaminated with bacteria. Adopted with a final implementation date of March 1, 2004, the AABB Standard reads “The blood bank or transfusion service shall have methods to limit and detect bacterial contamination in all platelet components.”

This Joint ASH and AABB Educational Session reviews the risks, testing strategies, and regulatory approaches regarding bacterial contamination of blood components to aid in preparing practitioners of hematology and transfusion medicine in understanding the background and clinical relevance of this clinically important issue and in considering the approaches currently available for its mitigation, as well as their implementation.

In this chapter, Drs. Hillyer and Josephson review the background and significance of bacterial contamination, as well as address the definitions, conceptions and limitations of the terms risk, safe and safety. They then describe current transfusion risks including non-infectious serious hazards of transfusion, and current and emerging viral risks. In the body of the text, Dr. Blajchman reviews the prevalence of bacterial contamination in cellular blood components in detail with current references to a variety of important studies. He then describes the signs and symptoms of transfusion-associated sepsis and the sources of the bacterial contamination for cellular blood products including donor bacteremia, and contamination during whole blood collection and of the collection pack. This is followed by strategies to decrease the transfusion-associated morbidity/mortality risk of contaminated cellular blood products including improving donor skin disinfection, removal of first aliquot of donor blood, pre-transfusion detection of bacteria, reducing recipient exposure, and pathogen reduction/inactivation. In the final sections, Drs. Vostal, Epstein and Goodman describe the regulations and regulatory approaches critical to the appropriate implementation of a bacterial contamination screening and limitation program including their and/or the FDA’s input on prevention of bacterial contamination, bacterial proliferation, and detection of bacteria in transfusion products. This is followed by a discussion of sampling strategy for detection of bacteria in a transfusion product, as well as the current approval process for bacterial detection devices, trials recommended under “actual clinical use” conditions, pathogen reduction technologies, and bacterial detection and the extension of platelet storage.

Microbial contamination of cellular products for hematolymphoid transplantation therapy: assessment of the problem and strategies to minimize the clinical impact

BACKGROUND

Hematopoietic progenitor stem cells (HPSC) are a specialized transfusion product used for transplantation. Microbial contamination may occur during harvest or subsequent manipulation of these cells. The same difficulties in ensuring a safe, sterile, final product are faced in the preparation of other cell-therapy products directly obtained from donors. Detection of contamination is problematic, and the clinical significance of infusing contaminated HPSC is controversial.

METHODS

Chimeric Therapies' manufacturing and clinical experience with BM HPSC products and validation of a culture method for detection are described. In addition, this paper reviews the literature concerning contaminated blood products, including rates and circumstances of contamination, organisms, methods of detection, and the clinical significance of infusion of contaminated products.

RESULTS

Seven of 33 BM harvest products received at Chimeric Therapies were culture positive for skin commensal organisms. Three of seven were culture positive in the infused product. This compares with literature reports of 0-42%. No patients had significant infusion reactions or evidence of infection related to the contamination.

DISCUSSION

The risks associated with microbial contamination with skin commensals are insignificant compared with other components of transplantation. Contamination with pathogens can be eliminated with careful good manufacturing practices (GMP). A series of practical recommendations are presented for the reduction of contamination in HPSC and cell-therapy products.

Guidelines for the prevention of intravascular catheter-related infections

BACKGROUND

Although many catheter-related bloodstream infections (CRBSIs) are preventable, measures to reduce these infections are not uniformly implemented.

OBJECTIVE

To update an existing evidenced-based guideline that promotes strategies to prevent CRBSIs.

DATA SOURCES

The MEDLINE database, conference proceedings, and bibliographies of review articles and book chapters were searched for relevant articles.

STUDIES INCLUDED

Laboratory-based studies, controlled clinical trials, prospective interventional trials, and epidemiologic investigations.

OUTCOME MEASURES

Reduction in CRBSI, catheter colonization, or catheter-related infection.

SYNTHESIS

The recommended preventive strategies with the strongest supportive evidence are education and training of healthcare providers who insert and maintain catheters; maximal sterile barrier precautions during central venous catheter insertion; use of a 2% chlorhexidine preparation for skin antisepsis; no routine replacement of central venous catheters for prevention of infection; and use of antiseptic/antibiotic-impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies (ie, education and training, maximal sterile barrier precautions, and 2% chlorhexidine for skin antisepsis).

CONCLUSION

Successful implementation of these evidence-based interventions can reduce the risk for serious catheter-related infection.

Guidelines for the Prevention of Intravascular Catheter–Related Infections

These guidelines have been developed for practitioners who insert catheters and for persons responsible for surveillance and control of infections in hospital, outpatient, and home health-care settings. This report was prepared by a working group comprising members from professional organizations representing the disciplines of critical care medicine, infectious diseases, health-care infection control, surgery, anesthesiology, interventional radiology, pulmonary medicine, pediatric medicine, and nursing. The working group was led by the Society of Critical Care Medicine (SCCM), in collaboration with the Infectious Disease Society of America (IDSA), Society for Healthcare Epidemiology of America (SHEA), Surgical Infection Society (SIS), American College of Chest Physicians (ACCP), American Thoracic Society (ATS), American Society of Critical Care Anesthesiologists (ASCCA), Association for Professionals in Infection Control and Epidemiology (APIC), Infusion Nurses Society (INS), Oncology Nursing Society (ONS), Society of Cardiovascular and Interventional Radiology (SCVIR), American Academy of Pediatrics (AAP), and the Healthcare Infection Control Practices Advisory Committee (HICPAC) of the Centers for Disease Control and Prevention (CDC) and is intended to replace the Guideline for Prevention of Intravascular Device–Related Infections published in 1996. These guidelines are intended to provide evidence-based recommendations for preventing catheter-related infections. Major areas of emphasis include 1) educating and training health-care providers who insert and maintain catheters; 2) using maximal sterile barrier precautions during central venous catheter insertion; 3) using a 2% chlorhexidine preparation for skin antisepsis; 4) avoiding routine replacement of central venous catheters as a strategy to prevent infection; and 5) using antiseptic/antibiotic impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies (i.e., education and training, maximal sterile barrier precautions, and 2% chlorhexidine for skin antisepsis). These guidelines also identify performance indicators that can be used locally by health-care institutions or organizations to monitor their success in implementing these evidence-based recommendations.

Guidelines for the prevention of intravascular catheter-related infections

BACKGROUND

Although many catheter-related bloodstream infections (CR-BSIs) are preventable, measures to reduce these infections are not uniformly implemented.

OBJECTIVE

To update an existing evidenced-based guideline that promotes strategies to prevent CR-BSIs.

DATA SOURCES

The MEDLINE database, conference proceedings, and bibliographies of review articles and book chapters were searched for relevant articles.Studies Included: Laboratory-based studies, controlled clinical trials, prospective interventional trials, and epidemiological investigations.

OUTCOME MEASURES

Reduction in CR-BSI, catheter colonization, or catheter-related infection.

SYNTHESIS

The recommended preventive strategies with the strongest supportive evidence are education and training of healthcare providers who insert and maintain catheters; maximal sterile barrier precautions during central venous catheter insertion; use of a 2% chlorhexidine preparation for skin antisepsis; no routine replacement of central venous catheters for prevention of infection; and use of antiseptic/antibiotic impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies (i.e. education and training, maximal sterile barrier precautions and 2% chlorhexidine for skin antisepsis).

CONCLUSION

Successful implementation of these evidence-based interventions can reduce the risk for serious catheter-related infection.

Guidelines for the prevention of intravascular catheter-related infections. The Hospital Infection Control Practices Advisory Committee, Center for Disease Control and Prevention, U.S

These guidelines have been developed for practitioners who insert catheters and for persons responsible for surveillance and control of infections in hospital, outpatient, and home health-care settings. This report was prepared by a working group comprising members from professional organizations representing the disciplines of critical care medicine, infectious diseases, health-care infection control, surgery, anesthesiology, interventional radiology, pulmonary medicine, pediatric medicine, and nursing. The working group was led by the Society of Critical Care Medicine (SCCM), in collaboration with the Infectious Disease Society of America (IDSA), Society for Healthcare Epidemiology of America (SHEA), Surgical Infection Society (SIS), American College of Chest Physicians (ACCP), American Thoracic Society (ATS), American Society of Critical Care Anesthesiologists (ASCCA), Association for Professionals in Infection Control and Epidemiology (APIC), Infusion Nurses Society (INS), Oncology Nursing Society (ONS), Society of Cardiovascular and Interventional Radiology (SCVIR), American Academy of Pediatrics (AAP), and the Healthcare Infection Control Practices Advisory Committee (HICPAC) of the Centers for Disease Control and Prevention (CDC) and is intended to replace the Guideline for Prevention of Intravascular Device-Related Infections published in 1996. These guidelines are intended to provide evidence-based recommendations for preventing catheter-related infections. Major areas of emphasis include 1) educating and training health-care providers who insert and maintain catheters; 2) using maximal sterile barrier precautions during central venous catheter insertion; 3) using a 2% chlorhexidine preparation for skin antisepsis; 4) avoiding routine replacement of central venous catheters as a strategy to prevent infection; and 5) using antiseptic/antibiotic impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies (ie, education and training, maximal sterile barrier precautions, and 2% chlorhexidine for skin antisepsis). These guidelines also identify performance indicators that can be used locally by health-care institutions or organizations to monitor their success in implementing these evidence-based recommendations.

Impact of donor arm skin disinfection on the bacterial contamination rate of platelet concentrates

BACKGROUND AND OBJECTIVES

Despite improved methods for detecting bacterial contamination of blood products, bacterial sepsis remains a significant risk in blood transfusion. This study was undertaken to investigate whether adopting a different skin disinfection protocol could reduce the rate of bacterial contamination of platelet concentrates.

MATERIALS AND METHODS

Two skin disinfection protocols were consecutively used in the routine blood collection setting during two 10-month periods: 0.5% cetrimide/0.05% chlorhexidine solution followed by 70% isopropyl alcohol (first 10-month time-period); and 10% povidone-iodine followed by 70% isopropyl alcohol (second 10-month time-period). The rates of bacterial contamination of platelet concentrates were monitored by using a surveillance programme described previously.

RESULTS

The overall bacterial contamination rate in the first time-period was 0.072%. After introduction of the povidone-iodine and isopropyl alcohol protocol, the bacterial contamination rate decreased to 0.042% (relative risk reduction: -0.42; 95% confidence interval, -0.12 to -0.61, P= 0.009). There were no differences in the types of micro-organisms identified (P = 0.7).

CONCLUSIONS

Skin disinfection by povidone-iodine and isopropyl alcohol is more effective than that by cetrimide/chorhexidine and isopropyl alcohol in reducing venepuncture-associated contamination of platelet concentrates by skin flora. Our data indicate that the disinfection protocol should be used on a routine basis and such implementation should translate into a significant improvement in blood safety to patients receiving platelet transfusion.

Experience with universal bacterial culturing to detect contamination of apheresis platelet units in a hospital transfusion service

BACKGROUND

Bacterial contamination of platelet units poses one of the greatest risks of morbidity and mortality to platelet transfusion recipients. A routine culture of all units (WBC-reduced apheresis platelet units) was instituted on Day 2 over a 2-year period to reduce this risk.

STUDY DESIGN AND METHODS

A sterile connecting device was used to attach a small transfer pack on the morning of Day 2 after collection, and 10 mL of the unit were transferred to the small bag. After disconnection from the unit, about half of this volume was transferred to an aerobic culture bottle of an automated bacterial detection system. Units were maintained in available inventory until and unless a report was received of growth in the sample. When available, the unit or a retained aliquot was recultured if the initial sample was positive. Units were held up to 2 days beyond their 5-day outdate and used for transfusion if no other suitable units were available to meet the clinical need or were evaluated with in vitro testing on Day 8.

RESULTS

Of 2678 units cultured, 16 (0.6%) were positive on initial culture. Thirteen could be recultured, and all of these samples were negative. Shortly after the 2-year period of the study, two units (split from the same collection) were documented as growing coagulase-negative Staphylococci 12 hours after sampling. Units transfused on Day 6 or 7 (n = 40) yielded expected clinical responses, and CCI available on 21 cipients 10 to 60 minutes after transfusion demonstrated acceptable results (mean, 14,400 +/- 8800; median, 12,191; 90% > 7500). More than 96 percent of units tested on Day 8 had pH greater than 6.2 and continued to demonstrate swirling.

CONCLUSIONS

Routine culturing of apheresis platelet units is feasible, can be accomplished with a low rate of false positivity, and can detect contaminated units. The cost of such a protocol could be mitigated with extension of the storage period, and clinical experience with units held for 6 or 7 days was satisfactory.

Bacterial contamination of blood products: factors, options, and insights

Transfusion of bacterially contaminated blood products remains an overlooked problem. However, the risk of receiving a bacterially contaminated unit is greater than the combined risk of HIV-1/2, HCV, HBV, and HTLV I/II [American Association of Blood Banks Bulletin, no. 294, 1996]. Topics covered in this article include: the current incidence, clinical presentation and outcome, effective methods of detection, and ways to reduce bacterial contamination of blood products. There is no one existing strategy that can completely eliminate the risk of bacterial contamination. It is inevitable that partial solutions or combinations of methods will be implemented in the near future.

Electrochemiluminescent detection of bacteria in blood components

Transfusion-transmitted bacterial infections cause significant patient morbidity and mortality. This study aimed to improve the sensitivity of a nucleic acid-based electrochemiluminescence (ECL) assay for pretransfusion bacterial testing of cellular blood components. The approach is dependent on the detection of bacterial 16S ribosomal RNA (rRNA). The modifications studied included the use of a chaotrope-based lysis buffer with high-energy mechanical cell disruption by RiboLysis, increased ruthenium (Ru2+) labelling per 16S rRNA molecule and concomitant use of fluorescent nucleic acid dyes (CyQUANT, Syto 17 red and Syto 61 red). The methodological changes made did lead to more effective bacterial cell disruption and enhanced ECL signal generation. Nevertheless, assay sensitivity was only slightly improved at approximately 10(4)-10(5) colony forming units per mL (CFU mL(-1)) and the results were highly inconsistent. The method is still not sensitive to the required 10(2) CFU mL(-1) and remains impractical for routine use in blood centres.

Management of intravascular devices to prevent infection

Intravenous therapy is an essential part of clinical care used in a wide variety of healthcare settings. Thus, intravenous catheters have become indispensable to clinical practice. However, catheter-related-bloodstream infections (CR-BSIs) are a major source of morbidity and mortality, especially in hospital patients. Strategies to prevent infection need to change and develop to reflect the advances in technology and delivery of health care. Current guidance recommends a number of strategies to reduce the incidence of CR-BSIs. These include applying the principles of asepsis, the choice of catheter material, the site of insertion and when to replace equipment used. This article reviews the guidelines for current clinical practice.

Transfusion-transmitted bacterial infection in the United States, 1998 through 2000

BACKGROUND

Bacterial contamination of blood components can result in transfusion-transmitted infection, but the risk is not established.

STUDY DESIGN AND METHODS

Suspected cases of transfusion-transmitted bacteremia were reported to the CDC by participating blood collection facilities and transfusion services affiliated with the American Red Cross, AABB, or Department of Defense blood programs from 1998 through 2000. A case was defined as any transfusion reaction meeting clinical criteria in which the same organism species was cultured from a blood component and from recipient blood, with the organism pair confirmed as identical by molecular typing.

RESULTS

There were 34 cases and 9 deaths. The rate of transfusion-transmitted bacteremia (in events/million units) was 9.98 for single-donor platelets, 10.64 for pooled platelets, and 0.21 for RBC units; for fatal reactions, the rates were 1.94, 2.22, and 0.13, respectively. Patients at greatest risk for death received components containing gram-negative organisms (OR, 7.5; 95% CI, 1.3-64.2; p = 0.009).

CONCLUSION

Bacterial contamination of blood is an important cause of transfusion-transmitted infection; infection risk from platelet transfusion is higher compared with that from RBCs, and, overall, the risk of infection from bacterial contamination now may exceed that from viral agents. Recipients of components containing gram-negative organisms are at highest risk for transfusion-related death. The results of this study may help direct efforts to improve transfusion-related patient safety.

Transfusion-related bacterial sepsis

Transfusion-associated bacterial sepsis is a persistent problem in transfusion medicine, posing a greater threat than the combined risks of receiving a blood product contaminated with HIV-1 or 2, hepatitis C virus (HCV), hepatitis B virus (HBV), and human T-cell lymphtrophic virus (HTVL) -I or -II. This article provides a brief overview of the current incidence, clinical presentation, associated blood products and organisms, and the most feasible and effective methods available to reduce the potential risk of transfusion-associated sepsis. Because bacterial contamination of blood products is the most frequent cause of transfusion-transmitted infectious disease, and as no single existing strategy can completely eliminate its risk, it is important that clinical suspicion be high, and any partial solutions additively be implemented.