ABSTRACT
BACKGROUND AND OBJECTIVES: To reduce the risk of transfusion-transmitted malaria (TTM) from transfusible components, Australia tests for malaria antibodies in both travellers returning from and former residents of malaria-endemic areas. The testing is performed a minimum of 120 days after last potential exposure. TTM is an extremely rare event and managing the risk adds considerable complexity. The objectives of this study were to analyse various testing and deferral strategies, considering the risk, donation numbers and operational complexities. MATERIALS AND METHODS: A residual risk model was developed to calculate the risk of TTM in five testing/deferral strategies. Australian blood donor data from 2020 and 2021 were used and incorporated the incidence of parasitaemia, Plasmodium species and the malaria enzyme immunoassay test's failure rate. Donor and donation loss or gain and an operational assessment were performed. RESULTS: The current model's estimated risk of TTM is 1 in 67.9 million transfused units. Testing residents with a 120-day plasma restriction for visitors without testing was found to have the same estimated risk, with an expected increase of 342 donations per year, significant cost savings and a 62% reduction in the number of donors requiring assessment. CONCLUSION: A strategy that involves testing residents of malaria areas only and a 120-day plasma travel restriction would not significantly increase the risk of TTM, is operationally simpler, costs less and results in a small increase in donations.
ABSTRACT
BACKGROUND AND OBJECTIVES: The risk of transfusion-transmitted malaria (TTM) infections is extremely low in Australia, and the cost-effectiveness of the current screening strategy has not been assessed. This study aims to conduct a cost-effectiveness analysis of different malaria screening strategies in blood donors as part of the risk-based decision-making framework. MATERIALS AND METHODS: A decision tree model was developed to assess the cost-effectiveness of five alternative malaria screening strategies from a healthcare sector perspective. Screening strategies combining total or partial removal of malaria testing with different deferral periods were considered. The probabilities of developing severe and uncomplicated TTM were based on a literature review of cases in non-endemic areas since 2000. The health outcomes were quantified using disability-adjusted life years. The costs of non-returning donors due to deferral were also included. Deterministic and probabilistic sensitivity analyses were conducted to account for data uncertainty. RESULTS: The residual risks for all strategies were so low that the costs, mortality and morbidity associated with TTM are almost negligible. The overall costs were predominantly influenced by the costs of non-returning blood donors. As a result, removal of malaria testing and applying a 28-day deferral for at-risk donors were the least costly and most cost-effective of all the options considered. CONCLUSION: The current screening strategy for malaria in blood donors in Australia is not an efficient use of healthcare resources. Partial or total removal of malaria testing would bring significant cost savings without significantly compromising blood safety.
