Malaria Blood Smear
Malaria is the parasite most commonly seen in the blood in the United States. Microscopic examination of Giemsa stained peripheral blood smears for trophozoites, schizonts, or gametocytes is the best diagnostic test.
Ideally, blood should be drawn in the middle of the paroxysm of chills and fever, because the greatest number of parasites is likely to be present in the blood at this time. Since paroxysms cannot always be predicted, smears should be taken at intervals of 6 to 18 hours for three successive days. Each smear should be examined immediately. Negative smears for three consecutive days during symptoms are consistent with the absence of malarial infection.
Reference value is negative, meaning no parasites were seen. If positive, the organism is identified.
The preferred specimen is three thin and thick smears made at the bedside. If not possible, draw one 5 mL lavender top (EDTA) tube.
