Padronização de esfregaço sanguíneo preparado em acetato transparente, como alternativa para o ensino do diagnóstico parasitológico da malária

Abstract

Practical lessons of malaria diagnosis by microscopy is part of the pedagogical process of academic training in medicine, biology, pharmacy and biomedicine students, in order to qualify them for a correct malaria diagnosis in their future practices. A good malaria practical lesson requires good teaching material, including glass slides containing positive blood smears. Loss of glass slides is frequently by careless students, by falling off and break them or by smear damage. To minimize this problem, the present study was designed to describe a methodology of preparation and validation of blood smears made on clear acetate film sheets, in order to implementing appropriate and more easily teaching resource available for teaching microscopic diagnosis of malaria. Several types of acetate film were tested. Thick and thin blood smears were prepared on it and subsequently stained by Walker and Giemsa methods, respectively. Small fragments of the stained acetate were cut and mounted onto glass slides for further microscopic examination. The evaluation of the quality of the new method was made by comparing the results of microscopic observation image and parasite density, performed by 3 microscopists. The study showed that transparent acetate films are feasible for making thick and thin blood smears to diagnosis malaria by microscopy. This is a simple and low cost technical implementation that does not compromise on morphological and tinctorial features of parasites nor of the blood cells into the smears. Because it is lightweight and flexible characteristics, the acetate film has the advantage of easy handling and transport. In addition, the acetate fragments containing stained blood smears can be reused if the glass slides breaks.