Prevention of transfusion ‐transmitted malaria

Transfusion‐transmitted malaria (TTM) occurs when the Plasmodium found in the transfusion recipient and corresponding blood donor are genotypically identical. All five species of Plasmodium are known to cause TTM. Transfusion transmission of Plasmodium has been estimated between 14 and 28 per cent in regions, where about a quarter to half of the population carries the parasite. The presentation and clinical severity of transfusion‐transmitted malaria may differ between malaria‐endemic and non‐endemic countries. Elements critical to outcomes in recipients include parasite load transfused, patient anti‐Plasmodium titre pretransfusion, per cent clearance of parasites and level of anti‐Plasmodium humoural immune response. Several strategies to prevent TTM include donor deferral, screening, prophylaxis and presumptive treatment and now pathogen reduction. Malaria testing is recommended for endemic countries, but there are no practical, affordable and suitably sensitive screening tests. Microscopy has limited sensitivity, whilst PCR though efficient is cost‐inhibiting. Donor screening in countries facing perennial blood shortages would drastically reduce blood availability. Practice across sub‐Saharan Africa shows no uniformity with screening. WHO advocates for presumptive antimalarial treatment of transfusion recipients in endemic countries, whilst guidelines for malaria programs require parasitological confirmation before medication. Improving safety of blood unit...
Source: ISBT Science Series - Category: Hematology Authors: Tags: Congress Review Source Type: research