Residual risk of transfusion transmitted human immunodeficiency virus, hepatitis B virus, hepatitis C virus and human T lymphotrophic virus
ABSTRACT The risk of transfusion transmitted viral infection is now so low that mathematical modelling is required to estimate the residual risk. The first national viral risk estimates for hepatitis B virus (HBV), human immunodeficiency virus (HIV) and hepatitis C virus (HCV) were recently published by the Australian Red Cross Blood Service. Using several refinements to the original methodology, as well as an additional 2 years of data, new risk estimates have been derived.
Viral screening data for Australian donors for 2000/2003 were retrospectively analysed. The data were applied to three published models to estimate the residual risk of transmitting HIV, HBV, HCV or human T lymphotrophic virus (HTLV) by blood transfusion in Australia.
Applying the three models to HBV, HIV and HCV, three point estimates of the residual risk per unit were calculated for each virus. The median point estimates were 1 in 1,339,000 for HBV, 1 in 1 in 7,299,000 for HIV, and 1 in 3,636,000 for HCV. Although the HTLV risk could not be equivalently calculated because of the lack of incident infection it was estimated to be considerably less than 1 in 1,000,000 using a separate method.
The most current and accurate estimate of residual risk of viral transmission in Australia has been provided in the present study. The residual risk in Australia is exceptionally small, continuing to decrease and is generally less than European or US risk estimates. These new estimates demonstrate that for viral transmission the Australian blood supply is amongst the safest in the world, and provide a basis for evaluating the cost benefit of future viral testing methodologies.
SourceAvailable from: jpathology.com[Show abstract] [Hide abstract]
ABSTRACT: Background: Selection of voluntary blood donors who are at low risk of transfusion-transmitted infec-tions is essential in maintaining the safety of the blood supply. Evaluation of the effectiveness of the predonation screening process may offer opportunities to further improve transfusion safety. Objective: To perform predonation screening of blood donors for transfusion transmitted infections. Material and Methods: A descriptive cross-sectional study was conducted in North West General Hospital and research center, Peshawar between May 2009 and October 2010. Predonation screening was performed by Immunochromatographic method for Hepatitis B surface antigen (HbsAg), Hepatitis C antibody (HCV Ab), Human immunodeficiency virus (HIV), syphilis by Venereal Disease Research Laboratories (VDRL) and malarial parasites by Giemsa stained peripheral blood film. Blood was col-lected in triple bags from all the donors initially found negative on primary screening. Results: A total of 1600 donors were tested, of these 113 (7.06%) were reactive for transfusion-transmitted infections. This comprised 50 (3.12%)cases positive for the presence of HbsAg, 23 (1.43%) cases positive for the presence of HCV Ab, 6 (0.37%) cases positive for the presence of HIV, 32 (2%) cas-es positive for VDRL, and 2 (0.12%) cases for gametocyte of Plasmodium falciparum. Conclusion: The 113 reactive cases of transfusion-transmitted infections affirm the effectiveness of current donor selection by predonation screening in reducing the residual risk of transfusion-transmitted infections, saving the cost of bags and added cost of decreased number of advanced screen-ing in donor bags.
[Show abstract] [Hide abstract]
ABSTRACT: To determine whether or not pre-donation testing of blood donors affords substantial cost savings without compromise to blood transfusion safety. Pre-donation testing of blood donors for Transfusion Transmissible Infections (TTIs) is done in most developing countries because substantial cost savings are made from resources, materials and man-hours which would have been spent to procure infected blood units. Simple rapid test kits used in pre-donation testing is not as sensitive as the Enzyme Linked Immuno-sorbent Assay (ELISA) method used in post-donation screening in a quality assured manner. It is a retrospective study where records of pre- and post-donation tests done in donor clinic of University of Ilorin Teaching Hospital, between January and December 2010 were retrieved. All processes and inputs were evaluated and costs calculated for pre-donation testing by simple rapid techniques and post donation screening by ELISA. 5000 prospective donors were tested in the study period. The cost of single rapid Pre-donation testing was less than that of single ELISA Post-donation screen. The cost of double rapid Pre-donation and Post donation ELISA screen exceeded the cost of single post donation ELISA screen. Substantial cost savings were made when single rapid Pre-donation testing is relied on. More blood units were found reactive for the TTIs with the more expensive Post-donation ELISA. Pre-donation testing of blood donors was not cost effective. Although, there is an apparent savings if pre-donation testing is not followed by post-donation ELISA testing, it is done at a compromise to blood transfusion safety.Ghana medical journal 09/2014; 48(3):158-62.
[Show abstract] [Hide abstract]
ABSTRACT: Powell-Dunford N, Quesada JF, Malsby RF, Chou V, Gerhardt RT, Gross KR, Shackelford SA. Risk management analysis of air ambulance blood product administration in combat operations. Aviat Space Environ Med 2014; 85:1130–5. Background: Between June–October 2012, 61 flight-medic-directed transfusions took place aboard U.S. Army Medical Evacuation (medevac) helicopters in Afghanistan. This represents the initial experience for pre-hospital blood product transfusion by U.S. Army flight medics. Methods: We performed a retrospective review of clinical records, operating guidelines, after-action reviews, decision and information briefs, bimonthly medical conferences, and medevac-related medical records. Results: A successful program was administered at 10 locations across Afghanistan. Adherence to protocol transfusion indications was 97%. There were 61 casualties who were transfused without any known instance of adverse reaction or local blood product wastage. Shock index (heart rate/systolic blood pressure) improved significantly en route, with a median shock index of 1.6 (IQR 1.2–2.0) pre-transfusion and 1.1 (IQR 1.0–1.5) post-transfusion (P Discussion: Potential risks of medical complications, reverse propaganda, adherence to protocol, and diversion and/or wastage of limited resources were important considerations in the development of the pilot program. Aviation-specific risk mitigation strategies were important to ensure mission success in terms of wastage prevention, standardized operations at multiple locations, and prevention of adverse clinical outcomes. Consideration of aviation risk mitigation strategies may help enable other helicopter emergency medical systems to develop remote pre-hospital transfusion capability. This pilot program provides preliminary evidence that blood product administration by medevac is safe.Aviation Space and Environmental Medicine 11/2014; 85(11). DOI:10.3357/ASEM.3851.2014 · 0.78 Impact Factor