Laboratory Findings
The diagnosis of malaria depends on the demonstration of parasites on a blood smear examined under a microscope.1, 2 Microscopic examination can give a quantitative value to the parasitemia, with more than 5% to 10% of erythrocytes being infected associated with high mortality rate.2 It is useful for the purpose of evaluating treatment to follow the percentage of infected erythrocytes serially.2
In P. falciparum malaria infection, additional laboratory findings may include mild anemia, mild decrease in blood platelets (thrombocytopenia), elevation of bilirubin due to the lysis of red blood cells, elevation of aminotransferases, albuminuria, and the presence of abnormal bodies in the urine (urinary "casts").1, 2 Acute renal failure with increased creatinine, proteinuria, and hemoglobinuria may also be present.
1 Hickman MS. Chapter VI.30: Malaria. Case Based Pediatrics for Medical Students and Residents. May 2003 [Web site]. Available at: http://www.hawaii.edu/medicine/pediatrics/pedtext/s06c30.html. Accessed June 15, 2006.
2 Centers for Disease Control and Prevention. Malaria: Topic home [Web site]. Available at: http://www.cdc.gov/Malaria/. Accessed June 6, 2006.