Testing for HTLV 1 and HTLV 2 among blood donors in Western Saudi Arabia: prevalence and cost considerations.

BACKGROUND: Screening all blood donors for human T-cell lymphotropic viruses 1 and 2 (HTLV 1 and HTLV 2) is mandatory in Saudi Arabia. The aim of this study is to evaluate the results and costs associated with the current testing policy for HTLV 1 and HTLV 2 in blood donors at King Abdulaziz University Hospital (KAUH), Jeddah. STUDY DESIGNS AND METHODS: Donor-testing results from Blood Transfusion Services at KAUH were reviewed over a 10-year period, from January 2006 through December 2015. All donors were screened using chemiluminescent microparticle immunoassay. Reactive samples were then tested by Western blot for confirmation. Costs associated with testing were calculated. RESULTS: Data of 107 419 donations in the study period were reviewed. Saudi nationals constituted 51 168 donors (47·6%). Of 107 419 blood donors tested for HTLV 1 and HTLV 2 antibody, and 95 (0·088%) donors were reactive to screening tests. None of the samples found to be reactive to screening tests was positive by Western blot. The average cost of testing was US$ 171 870 per year. CONCLUSION: No donors were confirmed to have HTLV 1 and HTLV 2 in this cohort exceeding 100 000 donors. We propose changes to the policy mandating universal testing by replacing it with universal leukodepletion coupled with targeted screening to donors coming from endemic area or donors at risk. Such changes are expected to lead to a reduction of testing cost without affecting safety.

Human T-cell lymphotropic virus testing of blood donors in Norway: a cost-effect model.

BACKGROUND: Human T-cell lymphotropic virus type I and II (HTLV-I and II) are human retroviruses that can be transmitted by transfusion of whole blood. An HTLV-I infection is associated with adult T-cell leukaemia (ATL) and with tropical spastic paraparesis (TSP). Antibody tests from 5.5 million European blood donors have shown that the HTLV prevalence is low, ranging from 0 to 0.02%. This paper examines costs and effects associated with the intervention of testing all new blood donors for HTLV. METHODS: A mathematical model was used to calculate the number of cases prevented by the intervention. For a given prevalence of HTLV in the blood donor population, the model calculates the number of recipients infected by transfusion, and the number of partners and offspring that will in turn be infected. The model then calculates the number of subjects with disease due to HTLV-I infection and the number of deaths from disease. From these numbers the measures of cost and effect are calculated. RESULTS: Testing all new blood donors for HTLV is calculated to cost US$ 9.2 million per life saved, or US$ 420,000 per quality adjusted life year gained by the intervention, when the HTLV prevalence among donors is 1 per 100,000. When the prevalence among donors is 10 per 100,000 the intervention will cost US$ 0.9 million per life saved, or US$ 41,000 per quality adjusted life year gained. The same analysis shows that testing blood donors for human immunodeficiency virus (HIV) saves money when the HIV prevalence among donors is above 0.7 per 100,000. CONCLUSION: For Norway, studies suggest a willingness to pay to save a statistical life of approximately US$ 1.2 million. The costs fall under this value when the number of infected persons is > or = 8 per 100,000 donors. The results are uncertain because of the uncertainty in HTLV infection and disease parameters.

[Quality adjusted life years in assessment of preventive measures. Should blood donors be tested for HTLV-I/II infections?]. / Kvalitetsjusterte leveår i vurderingen av forebyggende helsearbeid. Bør blodgivere testes for HTLV-I/II-infeksjon?

In planning preventive health measures, quality adjusted life-years (QALYs) are useful as a measure of benefit. As an example, the question of whether blood donors should be routinely tested for antibodies to the Human T-lymphotropic viruses I and II (HTLV I/II) is analysed. A mathematical model was set up to describe the consequences, in terms of lost life-years and years with disease due to transfusion-mediated infection (if testing is not performed) or years with reduced quality of life (in the case of testing). These future outcomes were discounted and converted to QALYs. The cost per QALY is about NOK 2.33 million when the prevalence is 1 per 50,000 blood donors, and is reduced to 190,000 per QALY when the prevalence is 10 per 50,000. Using QALYs in evaluation of preventive medicine can be complicated, and calls for cooperation between epidemiologists and health economists.