Differences between a control profile of light scattered by a control sample from a sample of whole blood and a detection profile of light scattered from a detection sample from the sample of whole blood with a detection agent added indicate malaria infection of the whole blood, where the light scattering is Mie scattering by an ensemble of scatterers in samples which are detection optimized to a concentration just low enough so that each scatterer which does scatter light scatters light only once, where the profiles are for light scattered between zero and five degrees.