Detection of malarial parasites in routine Wright-stained blood smears

Among four cases of malaria, parasites were initially detected in routine Wright-stained blood smears from three. In one of the three, malaria was not suspected until the organisms were seen during routine differential counting. In the fourth, review of the previously unstudied smear indicated that they should have been detectable during routine differential counting. The attention of laboratory personnel is directed to the need for alertness to the possibility that organisms, especially malarial parasites, may be detectable during routine blood film examination. It is suspected that emphasizing the need to look for parasites will not significantly increase the time consumed in such a study. Ability to detect parasites is yet another advantage of direct, as opposed to automated, differential counting.