The TBS were performed using 50 μL of whole blood collected by finger prick that were spread over a rectangular area of approximately 1.5 sq cm and were stained with freshly prepared 10% Giemsa stain.20 A total of 300 microscopic fields were examined before a slide was considered negative. When TBS were found positive, parasitemia was quantified by estimating the number of parasites counted in presence of 300 leukocytes and calculating absolute parasitemia according the leukocyte counts per μL. Smears were read by experienced microscopists and a random sample of TBS was subjected to quality control by a microscopist from the malaria control program.