Reliable assessment of malaria prevalence through village clinics.

In 4 villages in the Pakistani Punjab, clinic surveys (CS) provided similar results on total malaria and malaria species prevalence as those from mass surveys (MS)--and at a fraction of the effort. This was true at 3 different levels of malaria transmission. Both methods requiring blood films from all interviewed subjects are believed to be superior to the classical active (ACD) and passive (PCD) case detection methods which sample only patients with a history of recent fever. These latter methods would not detect the large population of oligo- and asymptomatic parasitaemic subjects in the semi-immune population of malaria endemic areas.