[Bacterial complications of blood transfusions]

[Evaluation of adherence to the regulations for declaration of notification of transfusion reactions with fever and chills. A study of the Association Inter-Régionale du Sud-Est d'Hémovigilance (AIRSEH)]

Febrile non-hemolytic transfusion reactions (FNHTR) are the most frequently reported acute adverse effects of blood products, and should be notified within 48 h according to the hemovigilance regulation. In order to study the conformity of these notifications and to search for factors associated with non-conformity, we retrospectively studied all FNHTR notified by voluntary centers of the AIRSEH group from 1st September 1994 to 31st December 1999. Seven hundred and sixty-one FNHTR were registered by 10 centers, most of them were benign (grade 1); 67.8% were non-conform. The non-conformity was associated with the number of biological investigations performed (median number, respectively, 4.24 and 2.94--P = 0.038--in non-conform and conform notifications--P = 0.038) in univariate analysis. Using a logistic regression model, center and severity were the only two factors significantly associated with non-conformity. Different center practices, and in particular the interface between the hospital and the blood bank, may be responsible for the effect center. Moreover, the non-conformity concerns first of all benign FNHTR. A stronger separation between alert and epidemiological surveillance is proposed in order to improve the notifications' conformity.

[Transfusion-transmitted bacterial infection: residual risk and perspectives of prevention]

Bacterial contamination of blood components represents today the highest infectious risk of blood transfusion, the risk is particularly high when it affects platelet concentrates. The residual risk of transfusion reaction due to bacterial contamination of platelets concentrates remains stable. For all severity 1 case occurs with 25,000 distributed platelets concentrates and 1 death occurs with 200,000 distributed units. In France, efforts have focused on the prevention of contamination during donation--involving measures such as rejecting the first few millilitres of donated blood and improving skin disinfection--and the prevention of bacterial proliferation in platelets concentrates--notably by removing leukocytes and ensuring high-quality storage of donated blood. Improving strategies for reducing the risks of bacterial contamination is one of the priorities of the French National Blood Transfusion Service (l'Etablissement français du sang-EFS). There is currently considerable debate about the relative importance of bacterial screening methods and methods for inactivating pathogens present in PC. Automated culture (Biomérieux) and the ScanSystem (Hemosystem) and BDS (Pall) method are the most advanced detection systems available, to our knowledge. In term of pathogen inactivation system for platelets, Intercept (Baxter) is nearing the commercial market. These new prevention have logistic and/or functional consequences that will require close scrutiny methods. A national study group is currently considering the consequences of each of these methods and should give its opinion at the end of the first half of 2003.

[Blood transfusion and bacterial risk]

Initial hemovigilance data confirm the incidence and severity of transfusion reactions due to the bacterial contamination of blood components (TRBC). With 18 deaths reported through the French hemovigilance network over the past 5 years, bacterial risks represent one of the major immediate complications of blood components (BC) transfusion. BC contamination may lead to more or less severe TRBC, depending on their origin: bacteria growth, the BC itself or unknown origin. Although the rate of donated blood or BC contamination is known (0.5% and 0.05%, respectively) it is still difficult to assess the actual incidence of TRBC, as it is difficult to identify them and relate them to transfusion. Likewise, better knowledge of bacteria, symptoms and outcome is required to improve prevention methods. Better prevention can reduce BC contamination and proliferation of bacteria at each stage of blood transfusion. Methods to detect BC contamination are still under investigation. Through continuous education of hemovigilance actors in identifying and dealing with TRBC, as well as drawing up procedures to perform inquiries and specific bacterial analyses, case reporting can be further improved in order to achieve more efficient prevention.

[Prevalence of bacterial contamination of standard platelet units: prospective study]

BACKGROUND

Platelet concentrates contaminated with bacteria are a main source of transfusion-associated sepsis. Several studies have reported a very wide incidence (0-10%) of contamination. The aim of this study is to assess the prevalence of bacterial contamination of standard platelet units at the regional blood transfusion center in Casablanca.

STUDY DESIGN AND METHODS

During 15.5 months, 3,458 platelet concentrates (PCs) were analysed. The plasma from the bag and the tube was homogenised. One-fifth of the tube contents were inoculated every day for five days in two tubes containing 2.5 mL of Tryptic soy broth. One tube was incubated at room temperature and the other at 37 degrees C for 24 hours. The bacteria were identified by standard procedures.

RESULTS

Twenty-five (0.72%) of 3,458 platelet bags were contaminated. Twenty-two bacteria (88%) were found in the platelet bags stored three days or more, of which 14 (56%) were Staphylococci coagulase negative, two Staphylococcus aureus, one alpha-haemolytic Streptococcus, four bacillus cereus, one Enterobacter cloacae, one Escherichia Coli and two Xanthomonas maltophilia.

CONCLUSION

The incidence reported in this series is higher than that reported by most authors.

[Blood transfusion and bacterial risk]

Initial hemovigilance data confirm the incidence and severity of transfusion reactions due to the bacterial contamination of blood components (TRBCs). With 18 deaths reported through the French hemovigilance network over the past five years, bacterial risks represent one of the major immediate complications of BC transfusion. BC contamination may lead to more or less severe TRBCs, depending on their origin: bacteria growth, the BC itself or unknown origin. Although the rate of donated blood or BC contamination is known (0.5% and 0.05%, respectively), it is still difficult to assess the actual incidence of TRBCs, as it is difficult to identify and relate them to transfusion. Likewise, a better knowledge of bacteria, symptoms, and outcome is required to improve prevention methods. Better prevention can reduce BC contamination and proliferation of bacteria at each stage of blood transfusion. Methods of detecting BC contamination are still under investigation. Through continuous education of hemovigilance participants in identifying and dealing with TRBCs, as well as drawing up procedures to perform inquiries and specific bacterial analyses, case reporting can be further improved, in order to achieve more efficient prevention.

[Surveillance of biocontamination of the environment of labile blood products: its role in a quality assurance program]

As part of a quality assurance approach aiming at reducing the risk of bacterial contamination of labile blood components (BC), their environment was submitted to a twofold quality control. A yearly control was carried out by the University Hospital Laboratory of Hygiene (UH-LH). Another control was regularly implemented by our Quality Control Laboratory. In accordance with this quality system, we focused our attention on decontamination procedures, control targets and the definition of an acceptable threshold. The analysis of results over 1 year showed that they can be considered as satisfactory when less than 40 CFU/100 cm2 are found. Quality sheets were developed, aimed at motivating our staff, adapting the decontamination procedures and initiating corrective measures. This quality programme allowed us to develop close collaboration links with the UH-LH and to play a role in the prevention of hospital-acquired infections.