Comparison of capillary and venous blood using blood film microscopy in the detection of malaria parasites: A hospital based study

Malaria mainly due to Plasmodium falciparum is associated with great morbidity and mortality in Sub-Saharan Africa especially in children under 5 years. In order to eradicate the disease and avoidcomplications that may arise from severe infection, there is need to improve in management which includes evaluation of the current diagnostic methods. Diagnosis of malaria in resource limited and developing countries is commonly done by the detection of bloodstages of the Plasmodia in Giemsa stained blood films by light microscopy. Blood films are commonly prepared using capillary orvenous blood. This study was aimed at comparing the sensitivity of capillary and venous blood in the detection of malaria parasites. Twoblood films were prepared from the capillary and venous blood, airdried, stained and examined following standard protocol by expert microscopists who were blinded from the results of the others. 150 participants including 95 (63.3%) women and 55 (36.7%) men were recruited for the study. The mean age of the participants was 30years (ranging from 7 to 66years). 44 (29.3%) of the 150 blood films prepared from capillary blood were found to be positive meanwhile26 (17.3%) of the 150 venous blood films were found to be positive. The difference in the rate of malaria parasite detection in capillaryblood smear was significantly higher than that with the venous blood (P=0.0109). No significant difference (P=0.8999) was observed between the capillary blood parasitaemia (3935parasites/mm³) and venous blood parasitaemia (3407parasites/mm³). No significant correlation was observed between the capillary and venous blood parasitaemia (r = 0.3497, P = 0.1842). We came to the conclusion that usage of capillary blood to diagnose malaria was more sensitive than venous blood and these findings may impact routine clinical practice; hence improve on the management of malaria in endemic areas. We recommend that studies that employ light microscopy to detect malaria parasites including the annual figures posted by the WHO, should state whether it was capillary or venous blood that was used to obtain data as it is evident from this study that the prevalence of malaria is dependent on the source of peripheral blood.

کلیدواژه ها:

Plasmodium ، Microscopy ، Bloodfilms ، Capillary ، Venous ، Prevalence ،