Malaria and Transfusion: A Neglected Subject Coming Back to the Forefront

The review article by Owusu-Ofori et al [1] clearly outlines the paucity of data available to address the considerable problem of malaria transfusion safety in areas where malaria is endemic. It shows that, despite using a tool with poor sensitivity (microscopic evaluation), a median prevalence of parasitemia of 10% was found, with wide variations according to location and season. The other assays available for testing, such as antigen assays ormolecular methods, have not been investigated for screening of donor blood. There is very little information regarding the distribution and potential role of the different Plasmodium species in transfusion-associated malaria transmission. The clinical impact of parasitemia on at-risk and semiimmune transfusion recipients was not appropriately studied, although an indication that semi-immunity might provide some level of protection was provided. In this context, this excellent review comes at a critical time, when the development of antimalarial resistance has become common enough to lead to the discontinuation of chloroquine therapy and to the reconsideration of anti-malarial strategies, with newer alternatives being considerably more expensive and less well tolerated. This increased cost makes the common practice of anti-malarial prophylaxis in recipients of blood transfusion difficult to sustain in areas of endemicity where resources are scarce. Such prophylaxis was particularly useful for protecting young children with no or little malarial immunity from developing acute and potentially fatal posttransfusion malaria. Older patients were assumed to have been repeatedly exposed to Plasmodium species and to have developed a sufficient level of semi-immunity to withstand the additional malarial burden associated with the transfusion of a parasitemic unit of blood. The strategy of giving anti-malarial therapy to transfusion recipients with unexplained fever and the lack of effort to diagnose the cause of such fevers has turned posttransfusion malaria into a neglected issue in sub-Saharan Africa (SSA).