Pathogen reduction/inactivation of products for the treatment of bleeding disorders:what are the processes and what should we say to patients?

Patients with blood disorders (including leukaemia, platelet function disorders and coagulation factor deficiencies) or acute bleeding receive blood-derived products, such as red blood cells, platelet concentrates and plasma-derived products. Although the risk of pathogen contamination of blood products has fallen considerably over the past three decades, contamination is still a topic of concern. In order to counsel patients and obtain informed consent before transfusion, physicians are required to keep up to date with current knowledge on residual risk of pathogen transmission and methods of pathogen removal/inactivation. Here, we describe pathogens relevant to transfusion of blood products and discuss contemporary pathogen removal/inactivation procedures, as well as the potential risks associated with these products: the risk of contamination by infectious agents varies according to blood product/region, and there is a fine line between adequate inactivation and functional impairment of the product. The cost implications of implementing pathogen inactivation technology are also considered

Comparison of Two Real-Time Quantitative Assays for Detection of Severe Acute Respiratory Syndrome Coronavirus

The new severe acute respiratory syndrome (SARS) coronavirus (CoV), described in February 2003, infected a total of 8,439 people. A total of 812 people died due to respiratory insufficiency. Close contact with symptomatic patients appeared to be the main route of transmission. However, potential transmission by blood transfusion could not be definitely excluded. Two real-time SARS-specific PCR assays were assessed for their sensitivities, agreement of test results, and intra-assay variabilities. Both assays rely on reverse transcription and amplification of extracted RNA. Dilutions of gamma-irradiated cell culture supernatants of SARS CoV-infected Vero E6 cells were prepared to determine the precisions, linear ranges, and accuracies of the assays. The linear range for the Artus RealArt HPA-Coronavirus assay (Artus assay) was 1 × 10(2) to 1 × 10(7) copies/ml, and that for the Roche LightCycler SARS CoV Quantification kit (Roche assay) was 1 × 10(4) to 2 × 10(8) copies/ml. The detection limit of the Roche assay was 3,982.1 copies/ml, whereas that of the Artus assay was 37.8 copies/ml. Detection limits were calculated with a standard preparation that was recommended for use by the World Health Organization. However, quantification of CoV in this preparation may be imprecise. In summary, both assays are suitable for quantitative measurement of SARS CoV at the high concentrations expected in sputum samples. The Artus assay is also suitable for detection of SARS CoV at the low concentrations found in serum samples

Detection of Usutu virus infection in a healthy blood donor from south-west Germany, 2012

From September 2011 until November 2012, 31 serum samples from German patients with clinically sus - pected acute Usutu virus (USUV) infections were tested for USUV-specific antibodies. All samples tested nega - tive. In addition, 4,200 serum samples from healthy blood donors from south-west Germany were collected in January 2012 and also analysed for the presence of specific antibodies. One sample tested positive for USUV-IgG and -IgM. Thus, the seroprevalence of USUV antibodies in healthy blood donors from south-west Germany was low in January 2012

Enlargement of the WHO international repository for platelet transfusion-relevant bacteria reference strains

Background and ObjectivesInterventions to prevent and detect bacterial contamination of platelet concentrates (PCs) have reduced, but not eliminated the sepsis risk. Standardized bacterial strains are needed to validate detection and pathogen reduction technologies in PCs. Following the establishment of the First International Reference Repository of Platelet Transfusion-Relevant Bacterial Reference Strains (the repository'), the World Health Organization (WHO) Expert Committee on Biological Standardisation (ECBS) endorsed further repository expansion. Materials and MethodsSixteen bacterial strains, including the four repository strains, were distributed from the Paul-Ehrlich-Institut (PEI) to 14 laboratories in 10 countries for enumeration, identification and growth measurement on days 2, 4 and 7 after low spiking levels [10-25 colony-forming units (CFU)/PC bag]. Spore-forming (Bacillus cereusPEI-B-P-07-S, Bacillus thuringiensisPEI-B-P-57-S), Gram-negative (Enterobacter cloacaePEI-B-P-43, Morganella morganiiPEI-B-P-74, PEI-B-P-91, Proteus mirabilisPEI-B-P-55, Pseudomonas fluorescensPEI-B-P-77, Salmonella choleraesuisPEI-B-P-78, Serratia marcescensPEI-B-P-56) and Gram-positive (Staphylococcus aureusPEI-B-P-63, Streptococcus dysgalactiaePEI-B-P-71, Streptococcus bovisPEI-B-P-61) strains were evaluated. ResultsBacterial viability was conserved after transport to the participating laboratories with one exception (M.morganiiPEI-B-P-74). All other strains showed moderate-to-excellent growth. Bacillus cereus, B.thuringiensis, E.coli, K.pneumoniae, P.fluorescens, S.marcescens, S.aureus and S.dysgalactiae grew to >10(6) CFU/ml by day 2. Enterobacter cloacae, P.mirabilis, S.epidermidis, S.bovis and S.pyogenes achieved >10(6) CFU/ml at day 4. Growth of S.choleraesuis was lower and highly variable. ConclusionThe WHO ECBS approved all bacterial strains (except M.morganiiPEI-B-P-74 and S.choleraesuisPEI-B-P-78) for repository enlargement. The strains were stable, suitable for spiking with low CFU numbers, and proliferation was independent of the PC donor