Malaria parasite density estimation using actual and assumed white blood cell counts in Plasmodium falciparum-infected patients in Dak Lak province, Vietnam

Estimating malaria parasite density is necessary for disease management, clinical trials and drug efficacy studies. This study was conducted to compare the malaria parasite density among patients using actual white blood cell (WBC) and the assumed WBC counts (8.0 ×109/l). A cross-sectional study was conducted in Dak Lak, Vietnam. WBC and asexual malaria parasite counts were performed on blood films. Eighty patients were enrolled. The mean (±SD) of WBCs was 5.84±1.63 ×109/l. The median (IQR) of parasite density using the assumed WBCs (8000 cells/µl) (11057.50 [2388.50-34210.75] rings/µl) was significantly higher than that estimation based on the actual WBC count (6898.61 [1892.12-24623.10] rings/µl) (p<0.001). Therefore, this study recommended the use of actual WBC count to estimate malaria parasite density in P. falciparum – infected patients in Dak Lak, Vietnam.