Despite the development of grade IV anemia (Hb level of <6.5 g/dl) in 16% of our cohort, with a mean decrease in hemoglobin levels of 2.3 g/dl over 14 days, only 4% of patients received transfusions, reflecting the scarcity of blood for transfusion in Africa. This evidence concerns the gene GSTM1 and anemia (phenotype).