Impact of donor deferrals for malaria on blood availability in the United States

BACKGROUND: US blood availability is negatively impacted by residence or travel-related deferrals designed to prevent transmission of human immunodeficiency virus type 1 group O, variant Creutzfeldt-Jakob disease, Leishmania, and malaria. Generally, travel and residence deferrals lack sensitivity and specificity to identify infected donors, particularly for malaria. This study evaluated trends in malaria deferrals and their impact on blood availability from 2000 through 2006. STUDY DESIGN AND METHODS: An American Red Cross (ARC) research database was used to monitor trends in deferrals for exposure to Plasmodium spp., the causative agents of malaria. Annual deferral rates were classified as travel, residence, and history of malaria during 2000 through 2006. Overall yearly donation rates for acceptable donors were determined and used to estimate donations lost due to malaria-related deferrals. RESULTS: Approximately 29 million donors presented at ARC collection sites and 316,495 (1.1%) were deferred for malaria risk. More than 91 percent of malaria deferrals were for travel to endemic countries; travel deferrals showed a significant increase (p < 0.001) throughout the study period. Calculations of yearly donation rates suggested that more than 540,000 potential ARC blood donations were lost to malaria deferrals during the 7-year period. CONCLUSIONS: The vast majority of malaria deferrals were for travel to endemic areas; however, few US donors visit those areas associated with most US cases of malaria or transfusion-transmitted malaria. Current interventions fail to capture many semi-immune donors, those at greatest risk for transmitting infection. Considerations should be given to selective screening and permanent deferral of donors with a history of malaria.