Parasite density and the spectrum of clinical illness in falciparum malaria.

OBJECTIVE To determine the impact of percentage parasitemia and clinical features on morbidity and mortality in patients with P. falciparum malaria. STUDY DESIGN Case series. PLACE AND DURATION OF STUDY Department of Medicine, Medical Unit II, Jinnah Postgraduate Medical Centre, Karachi, Pakistan from May to November 2005. PATIENTS AND METHODS Seventy-six adult patients of smear positive P. falciparum malaria were selected for the study. Parasite density was estimated on thin blood film and expressed as percentage of red blood cells parasitized. Patients were divided into three groups on the basis of parasite density. The data was analyzed on SPSS version 12. Results were expressed as percentages, mean and standard deviations. P-value <0.05 was taken as significant. RESULTS Data of 76 study patients who fulfilled the inclusion criteria was analyzed on the basis of parasite density. Thirty-one (40.79%) patients had parasite density < 5%, 22 (28.95%) had parasite densities between 5% and 10% and 23(30.26%) patients had parasite density >10%. Comparative analysis of the groups showed that pallor, impaired consciousness, jaundice or malarial hepatitis, thrombocytopenia, acute renal failure, DIC, and mortality were all strongly associated with the density of Plasmodium falciparum malaria (p=0.001). Parasite density was not related to age, gender and hepatosplenomegaly. CONCLUSION High parasite density was associated with severe clinical illness, complications and mortality. Parasite counts of > 5% may be considered as hyperparasitaemia in this population of the world.