Comparison of Plasmodium Falciparum Densities using Assumed WHO Reference Value and Actual White blood cells Count in Gadarif state

Abstract

Abstract Estimating malaria parasite density (number of parasites per μl of blood) is necessary for disease management, clinical trials and drug efficacy studies. This is a descriptive cross sectional study to assess the agreement between the parasite density values obtained with the assumed value of 8,000 cells/μl, of white blood cells (WBCs) count which was set by WHO, and the actual (WBCs) count in P.falciparum patients in Gadarif state. Moreover, the most suitable assumed values of WBCs for that population was estimated. The effect of age, gander, fever, severity of malaria and other diseases on the white blood cells was analyzed. This study included 243 patients with uncomplicated P.falciparum malaria of both sex in the age group (1-71) years, they were interviewed according to a specially designed questionnaire form and venous blood samples were collected from each after verbal consent. Blood samples were collected in K 3 EDTA container, automated hematology analyzer (Mindray BC- 3000Plus) was used for WBCs count, and ideal thick blood film was prepared for estimating parasite densities after staining by using Giemsa stain. Parasite densities (parasite/μl of whole blood) was calculated using assumed value of 8,000 cells/μl, of (WBCs) count and the actual (WBCs) count of patients. Result were analyzed using computerize statistical package for social science (SPSS, version16). It was found that WBC counts were not significantly different between patients of different gender and body temperature (P.value >0.05), whereas they were significantly different between age groups of patients and other diseases groups (P.value =0.0001). The median parasite densities calculated with the actual WBC counts (7,825/μl) and the assumed WBC count of 8,000/μl (11,520/μl) were significantly different as (P.value <0.001) a result using of assumed WBC count of 8000 cells/μl to estimate parasite densities of P. falciparum malaria in Gadarif state lead to an overestimation. More realistic assumed WBC count for P.falciparum density was then estimated to be 5,500/μl for best estimated parasite densities. This study provides more realistic assumed WBC counts for estimating parasite densities in P.falciparum patients from other areas of Gadarif state.‫ا‬‫