Papers

Screening for human T cell leukaemia/lymphoma virus among blood donors in Sweden: cost effectiveness analysis

Elsa Tynell, specialist, infectious diseases, ^a Soren Andersson, immunologist, ^b Eva Lithander, senior officer, ^c Malin Arneborn, nurse epidemiologist, ^b Jonas Blomberg, associate professor, ^d Hans Bertil Hansson, county medical officer, ^e Aud Krook, associate professor, ^f Mats Nomberg, head of computer department, ^g Kristina Ramstedt, epidemiologist, ^b Agneta Shanwell, associate professor, ^g Anders Bjorkman, associate professor. ^a

^a Division of Infectious Diseases, Karolinska Institutet, Danderyd University Hospital, Danderyd, Sweden, ^b Swedish Institute for Infectious Disease Control and Karolinska Institutet, Stockholm, Sweden, ^c National Board for Health and Welfare, Stockholm, Sweden, ^d Section of Virology, Department of Medical Microbiology, University of Lund, Lund, Sweden, ^e Regional Centre for Communicable Disease Control, University Hospital MAS, Malmo, Sweden, ^f Division of Infectious Diseases, Karolinska Institutet, Huddinge University Hospital, Huddinge, Sweden, ^g Division of Transfusion Medicine, South Hospital, Stockholm

Correspondence to: Dr Tynell elsa.tynell{at}inf.ds.sll.se

Objective: To analyse the cost effectiveness of a national programme to screen blood donors for infection with the human T cell leukaemia/lymphoma virus.
Design: Three models for calculating the costs and benefits of screening were developed. The first model analysed the cost of continuously testing all donations; the second analysed the cost of initially testing new blood donors and then retesting them after five years; the third analysed the cost of testing donors only at the time of their first donation. Patients who had received blood components from donors confirmed to be infected with the virus were offered testing.
Setting: Sweden.
Main outcome measures: Prevalence of infection with the virus among blood donors, the risk of transmission of the virus, screening costs, and the outcome of infection.
Results: 648 497 donations were tested for the virus; 1625 samples tested positive by enzyme linked immunosorbent assay. 6 were confirmed positive by western blotting. The prevalence of infection with the virus was 2/100 000 donors. 35 patients who had received blood infected with the virus were tested; 3 were positive. The cost of testing every donation was calculated to be $3.02m (£1.88m); this is 18 times higher than the cost of testing new donors only, and only 1 additional positive donor would be discovered in 7 years. Regardless of the model used, screening was estimated to prevent only 1 death every 200 years at a minimum cost of $36m (£22.5m).
Conclusion: Based on these estimates the Swedish National Board of Health and Welfare decided that only new blood donors would be screened for infection with the virus.