For thin smears, the percent of infected RBCs is determined by counting the number of infected RBCs in relation to the number of uninfected RBCs. A minimum of 500 RBCs should be counted:
(Number of infected RBCs ÷ Total number of RBCs counted) x 100 = Percent Infected RBCs
Of note: multiple infected RBCs are counted as one, and gametocytes are not calculated.
