Hemoglobin levels related to days of illness, race, and Plasmodium species in Colombian patients with uncomplicated malaria.

Prevalence of malaria-related anemia in disease-endemic regions of the American continents has been poorly studied. We describe the relationships between hemoglobin level and race, Plasmodium species, and days of illness in 150 Colombian patients with uncomplicated malaria diagnosed by thick blood smear. Hemoglobin was measured at admission and a standardized questionnaire was used to determine days of illness and other variables. Associations between hemoglobin and the variables were estimated and adjusted according to the other covariates using regression analysis. Plasmodium falciparum and P. vivax were found in similar proportions and mild anemia was present in 50% of the patients. Volunteers were classified as Afro-Colombians (61%) and non-Afro-Colombians (39%). An inverse relationship between hemoglobin and days of illness was identified, and a statistical interaction was found between race and P. falciparum infection in determining the hemoglobin concentration. These observations could guide the design of research to better understand malarial anemia.