Box 1 Criteria for assessing quality of malaria blood film slide according to national malaria laboratory diagnosis EQA scheme guideline [9]

Excellent

Gross appearance: Both thin and thick film prepared on the same slide, thick film 10 mm diameter, newsprint read under thick film before staining, 10 mm from frosted end and thick film and between thick and a thin film with distinct head, body and tail

Microscopic appearances: Demonstrates RBCs lysed in thick film and a monolayer of RBCs, with normal and abnormal morphology in thin film. Staining allows the trophozoites, gametocytes and/or schizonts and the white blood cells to be clearly distinguished against the background

Good

Gross appearance: Film with uneven tail, too thick, too wide or too long with uneven thickness

Microscopic appearance: Demonstrates a monolayer of RBCs, and fixed RBCs

Staining allows the trophozoites, gametocytes and/or schizonts malaria parasites and the white blood cells to be clearly distinguished against the background

Poor

Gross appearance: Film with ragged tail, too thick, too wide or too long with uneven thickness

Microscopic appearance: Distorted appearance of the RBCs, malaria parasite and the white cells. It is difficult to spot fields with monolayer of cells and distorted appearance of the RBCs, malaria parasite, and the white cells