Bacterial Contamination Of Blood Products Research Articles

Practice Guidelines for Perioperative Blood Transfusion and Adjuvant Therapies

Practice Guidelines for Perioperative Blood Transfusion and Adjuvant Therapies

Effects of skin disinfection method, deviation bag, and bacterial screening on clinical safety of platelet transfusions in the Netherlands

Bacterial contamination of blood products is a great hazard for development of fatal transfusion reactions. Bacterial screening of platelet concentrates (PC) by aerobic and anaerobic culturing (BacT/ALERT, bioMérieux) was introduced in the Netherlands in October 2001. In November 2002, a nationwide, uniform skin cleansing method was introduced with a double-swab disinfection with 70 percent isopropyl alcohol. One location routinely used an integrated diversion bag to collect the first 20 to 30 mL. Over the calendar years 2002 and 2003, in total 113,093 PCs derived from pooled buffy coats were screened. After introduction of the new disinfection method, 0.85 percent were initially positive. This was a small reduction compared to the previous disinfection methods under which 0.95 percent were initially positive. The location with use of the diversion bag showed a significantly lower frequency of bacterial contamination, with 0.50 percent before and 0.37 percent after introduction of 70 percent isopropyl alcohol. In addition 8000 apheresis PCs were also screened, showing 24 initially positive samples (0.30%). The use of the diversion bag and, to a lesser extent, the use of double swabs with 70 percent isopropyl alcohol, led to a reduction of contamination. As expected, predominant contamination with resident skin bacteria was reduced. The combination of diversion bag and new disinfection led to a frequency of initial positive results for pooled five-donor PCs, which is similar to that of single-donor apheresis PCs. Furthermore, the bacterial detection system and associated product recall procedures have been shown to be effective in preventing transfusion of contaminated PCs and/or related red cells, especially for rapidly growing bacteria.

Use of a pH meter for bacterial screening of whole blood platelets

Bacterial contamination of blood products is a leading cause of transfusion-related morbidity and mortality. Transfusion services are now compelled to employ methods of detecting bacteria in platelet (PLT) components. The use of pH screening of whole-blood PLTs (WBPs) was evaluated with a pH meter at the time of issue as a surrogate test for bacterial contamination. All WBPs selected for transfusion in May through September 2004 were tested individually for pH at time of issue. Those with a pH value of less than 7.0 were cultured in an automated culture system for 5 days. The white blood cell (WBC) and PLT counts in 56 representative WBP units that failed pH screening were compared to WBP units with acceptable pH values. Of the 37,060 WBP units that underwent pH screening, 405 had a pH value of less than 7.0 (1.1%). Four of those units were culture positive (1.0%) for Staphylococcus aureus, Bacillus subtilis, diphtheroids, and coagulase-negative Staphylococcus. Only one cocomponent red blood cell (RBC) unit was culture-positive and grew the same bacteria (S. aureus) as the WBP unit. The rate of pH failure increased with WBP storage length with the greatest rate of pH failures occurring in 5-day-old WBPs. The units that failed pH screening had significantly more WBCs and PLTs than units with acceptable pH values. pH screening of WBPs at issue prevented transfusion of bacterially contaminated WBPs and RBCs. This method, however, results in significant PLT wastage. Higher WBC and PLT content likely explains pH failures not due to bacterial contamination.

Skin plugs in phlebotomy puncture for blood donation

Contamination at the site of the donor's skin may occur despite proper disinfection, because pathogens in deeper regions (such as pores) may not be eliminated by skin disinfection. It is suspected that the cannula detaches fragments of tissue when it penetrates the skin; the tissue fragments may reach blood products and release pathogens there. In the present study we punctured piglet skin with cannulas commonly used for blood donation and performed histological as well as cytological investigations of the lavage fluid in the cannula to identify superficial skin cells and skin plugs. Histological specimens of the pierced skin showed frayed puncture sites with loosely attached tissue fragments. In the lavage fluid of the cannula, a collection of epidermal cells was found in one of 150 punctures. Our results confirm that the phlebotomy cannula may cause superficial tissue fragments to be punched out of the donor's skin during blood donation. This fact should be taken into account when devising methods to reduce bacterial contamination in blood products.

Bacterial contamination of blood components.

Blood for transfusion is a potential source of infection by a variety of known and unknown transmissible agents. Over the last 20 years, astounding reductions in the risk of viral infection via allogeneic blood have been achieved. As a result of this success, bacterial contamination of blood products has emerged as the greatest residual source of transfusion-transmitted disease. This paper summarizes the current status of detection, prevention, and elimination of bacteria in blood products for transfusion.

血小板輸血後に敗血症性ショックを呈し，Ｍｏｒｇａｎｅｌｌａ ｍｏｒｇａｎｉｉ菌による輸血後感染症が強く示唆された１例

We report a baby with septic shock caused by Morganella morganii (M. morganii) after a single donor-derived platelet transfusion. A 7-month old boy was admitted to Keio University Hospital and operated on to repair a hereditary cardiac defect. The cardiac failure and respiratory failure did not improve, and a second operation was performed about six months after the first. Twenty days postoperation, he received a single donor-derived platelet transfusion due to thrombocytopenia caused by disseminated intravascular coagulation. Chill and skin rash appeared one hour after the starting of transfusion, followed by a high-grade fever, hypotension and tachycardia at two hours, at which time the transfusion was stopped. Bacterial culture of the patient's blood and platelet concentrate were performed. Three days later, M. morganii was detected from both samples. Following the administration of ceftazidime, the fever gradually decreased and plasma CRP levels decreased, leading to the strong suspicion of M. morganii contamination of the platelet concentrate. To our knowledge, this is the first case reported of bacteria-contaminated blood transfusion by M. morganii. Outcome in this patient would not have been successful of the bacterial contamination of blood products had not been suspected.

Bacterial contamination of blood components.

1. Linda A Smith, PhD CLS(NCA)[⇑][1] 1. is Professor and Graduate Program Director at the University of Texas Health Science Center, San Antonio TX 2. Michelle S Wright-Kanuth, PhD CLS(NCA) 1. is Associate Professor, Department of Clinical Laboratory Sciences, University of Texas Medical Branch, Galveston TX 1. Address for correspondence: Linda A Smith PhD CLS(NCA), Professor and Graduate Program Director, Department of Clinical Laboratory Sciences, University of Texas Health Science Center, 7703 Floyd Curl Dr, San Antonio TX 78229-3900. (210) 567-6689, (210) 567-8875 (fax). smithla{at}uthscsa.edu As discussed in one of the companion articles, significant progress has been made in reducing the transfusion transmission of viral infections such as hepatitis B, hepatitis C, and HIV. Serologic testing of donors has decreased the risk for acquiring some viral diseases to less than one in a million. Now however, bacterial contamination of blood products has assumed a major role as a cause of morbidity and mortality in recipients of blood products.1,2 Although overall risk for acquiring a transfusion-transmitted bacterial infection is still relatively low, methods to detect infected donors are not available as they are for detection of virally-infected donors. Therefore, detection of bacterial contamination is more problematic and is usually recognized only when the recipient has a severe reaction following administration of the blood component. In fact, after acute hemolytic transfusion reactions, bacterial sepsis is the next most frequent causes of transfusion related fatalities.3,4 In this article we will discuss the major organisms associated with bacterial contamination of blood components, studies of prevalence of bacterial contamination and transfusion associated sepsis, and the methods developed or in development to detect and/or prevent contamination. BACTERIAL CONTAMINATION Bacterial contamination of blood units occurs at any one of the following points: collection, processing, pooling of components, or transfusion. Infrequently, it may be due to transient bacteremia in the donor.5-7 High bacterial concentrations are often responsible for a serious septic or fatal reaction in the recipient with most of these reactions occurring in the elderly, neonates, or patients immunocompromised by illness or… ABBREVIATIONS: AABB = American Association of Blood Banks; BaCon = bacterial contamination associated with transfusion reactions); CFU = colony forming units; RBC = red blood cell; SHOT = serious hazards of transfusion; UVA = ultraviolet A light. [1]: #corresp-1

Transfusion‐Associated Septic Reactions

SUMMARYTransfusion reactions associated with bacteria and/or their products, during or following a blood transfusion, were one of the earliest recognized complications of allogeneic blood transfusions. Bacterial contamination of blood products has, therefore, been a problem for many decades and, at the present time, is likely the most common microbiological cause of transfusion‐associated mortality and morbidity. Septic reactions associated with platelet concentrates appear to be much more common than those associated with contaminated red blood cells. The overall prevalence of contaminated cellular blood products has been estimated to be approximately 1 in 3000; however, the transfusion of contaminated platelet or red blood cell units may not necessarily be associated with clinically apparent morbidity in recipients because the majority of contaminated blood product units contain relatively few organisms. Unfortunately, though, in a minority of instances, contaminated blood product units contain clinically significant numbers of bacteria as well as endotoxins that may be associated with significant mortality and/or morbidity. The incidence of clinically evident severe septic episodes has not yet been clearly established, but is probably in the order of 1 per 50,000 platelet units transfused and 1 per 500,000 red blood cell units transfused. In recent years, a variety of interventions have been proposed, and in some instances implemented, in an effort to reduce this significant and potentially preventable transfusion risk.

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.

Bacterial contamination of platelet concentrates: Incidence, significance, and prevention

Severe transfusion reactions associated with bacteria and/or their products, during or following a blood transfusion, were one of the earliest recognized complications of allogeneic blood transfusions. Bacterial contamination of blood products has thus been a problem for many decades and at present is likely the most common microbiological cause of transfusion-associated morbidity and mortality. Transfusion-associated sepsis due to contaminated platelet concentrates appears to be much more common than that due to contaminated red blood cells. The overall incidence of contaminated cellular blood products is approximately 1 in 3,000. However, transfusion to a recipient of a contaminated platelet unit may not necessarily be associated with clinically apparent morbidity, because the majority of contaminated platelet units contain relatively few organisms. In a minority of instances, contaminated units contain large numbers of potentially virulent bacteria, as well as endotoxins, and their transfusion is often associated with significant recipient morbidity and mortality. The incidence of severe septic episodes has not been clearly established, but is probably of the order of 1 per 50,000 platelet units transfused. With heightened awareness in recent years of the possibility that platelet transfusion-associated septic episodes can occur, a variety of measures have been proposed, and in some cases implemented, to try to prevent and control this transfusion risk.

Bacterial contamination of blood products

Transfusion-associated septic reactions occurring during, or following, the transfusion of cellular blood components was one of the earliest recognised complications of allogeneic blood transfusions. The presence of bacteria in cellular blood products thus has been a problem for many decades and currently it is probably the most common microbiological cause of transfusion-associated morbidity and mortality.

Mechanisms of severe transfusion reactions

Serious adverse effects of transfusion may be immunologically or non-immunologically mediated. Currently, bacterial contamination of blood products, particularly platelets, is one of the most significant causes of transfusion-related morbidity and mortality. Septic transfusion reactions can present with clinical symptoms similar to immune-mediated hemolytic transfusion reactions and transfusion-related acute lung injury. Extremely high fever and/or gastrointestinal symptoms, in a transfusion recipient, may be indicative of sepsis. The diagnosis is based upon culturing the same organism from both the patient and the transfused blood component. Numerous organisms have been implicated as the cause of septic transfusion reactions. Due to different storage conditions, gram negative organisms are more often isolated from red blood cell components; gram positive organisms are more often isolated from platelets. Prevention of septic transfusion reactions is primarily dependent on an adequate donor history and meticulous preparation of the donor phlebotomy site. Visual inspection of blood components prior to transfusion is also vital to preventing these reactions. Several methods of detection of bacterial contamination and inactivation of pathogens are currently under active investigation.

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.

1b Acute transfusion reactions

The vast majority of blood transfusions are uneventful and the desired result is achieved safely. Nevertheless, about 10% of transfusion recipients may suffer some form of untoward effect, yet severe morbidity and mortality are relatively rare. Febrile non-haemolytic transfusion reactions due to the presence of white cell antibodies in the recipient are the commonest type of reaction; although these cause great discomfort to the patient, they are not life-threatening. Although a minority of severe transfusions reactions, such as transfusion related lung injury (TRALI) cannot be prevented, the vast majority of serious reactions are preventable. ABO incompatibility is the most common cause of immediate deaths following transfusion reactions and invariably occurs as a result of procedural errors resulting in mis-identification of the recipient. Appropriate monitoring of patients during blood transfusion will enable prompt remedial action. Serious reactions due to bacterial contamination of blood products are becoming increasingly common and meticulous cleansing of the donor's arm, storage of blood and blood components compliant with recommended standards and guidelines and examination of the unit before transfusion will prevent most of these reactions. Other preventable serious hazards are caused by accidental injection of water into the circulation, administering red cells through a small gauge cannula, inappropriate heating of blood prior to administration or accidental freezing. While every endeavour should be made to eliminate preventable hazards of transfusion, over-transfusion is unfortunately still a problem in many countries. In order to present serious adverse effects, clinicians should be mindful that blood transfusions should only be prescribed when the benefits clearly outweigh the risks.

Bacterial contamination of blood products and the value of pre-transfusion testing.

There has been a dramatic increase recently in the number of reports of septic episodes associated with both red cell and platelet concentrate transfusions. These reports suggest that transfusion-associated septic reactions may occur as often as 1 per 4000 platelet transfusions, however, the true incidence of the bacterial contamination of stored cellular blood components has not yet been established. Recently developed automated techniques for the detection of bacteria are much more rapid than direct plating techniques. Such rapid techniques can be used to monitor the sterility of cellular blood products with greater sensitivity than Gram staining; using a small aliquot of the blood product taken soon after collection. Using such equipment, the incidence of bacterial contamination of 15,838 random donor platelet concentrates collected over a six-month period was determined and evidence of bacterial contamination was found in 32. Seven were classified as confirmed, 10 as unconfirmed and 12 as non-confirmed positives. The confirmed positivity rate was thus 4.4 per 10,000. This rate represents the minimum incidence of bacterial contamination of platelet concentrates and the true rate is likely higher, as some of the unconfirmed positives are likely to have been found to be positives, had the original platelet concentrate been available for culture. The true positive rate is therefore estimated to be between 4.4 and 10.7 per 10,000. Given this rate of bacterial contamination, it is our contention that all platelet concentrate units be monitored for bacteriologic sterility prior to their issue.(ABSTRACT TRUNCATED AT 250 WORDS)

Hazards of Bacterial Contamination of Blood Products

Post-transfusion bacterial sepsis is infrequent. It is, however, associated with a high mortality due to septic shock. This reflects the release of endotoxin from gram negative bacteria. Lesser transfusion reactions are usually under-reported. These are frequently caused by gram positive bacteria. Gram positive species such as staphylococci and other skin surface organisms may be cultured from platelets stored at room temperature. Typically, gram negative "psychrophyllic" species which survive storage at 4 degrees C are cultured from stored refrigerated blood implicated in transfusion reactions. These include Yersinia enterocolitica, Pseudomonas fluorescens etc. Bacterial contamination of the blood supply can occur via an endogenous or an exogenous source. Endogenous donor bacteraemia due to Y.enterocolitica may be asymptomatic or may follow an episode of gastroenteritis. Exogenous infections occur through some defect in the usual collection practice. Transfusion-acquired syphilis is now extremely uncommon. In the third world, beside the need for effective screening for viral pathogens, infections with protozoa, in particular plasmodia, trypanosoma and leishmania remain a major obstacle to ensuring safe blood supplies. Prevention of transfusion reactions demands rigorous attention to details of collection, storage, reissuing and infusion of blood products, as well as prompt treatment, testing and reporting of suspected reactions.

Transfusion Reactions Due to Bacterial Contamination of Blood and Blood Products

Bacterial infections transmitted by blood or blood products, although rare, remain a serious threat to the recipient of a transfusion. We report on five cases of adverse reactions due to bacterial contamination of blood products, and we review 76 similar cases reported in the English-language literature. Most cases (70%) have been reported from the United States. Various sources of contamination have been suggested, including infection in the donor and invasion of the blood product during the process of collection, preparation, and storage. Frequent clinical manifestations are fever (80%), chills (53%), hypotension (37%), and nausea or vomiting (26%). The overall mortality is 35% (28 of 81 patients). In 38 patients (47%) the adverse reactions have appeared during transfusion; in the others the interval between completion of the transfusion and appearance of symptoms has ranged from 15 minutes to 17 days. A wide spectrum of bacteria have been implicated as causes of adverse reactions, with Pseudomonas species involved in 28% of episodes. Many such reactions are probably misdiagnosed or overlooked, the result being underestimation of the extent of the problem.