Malaria diagnosis with the haematology analyser Cell-Dyn 3500: What does the instrument detect?

The Cell-Dyn 3500 instrument could become a sensitive and specific tool in the diagnosis of malaria. The instrument appears to detect malaria-pigment within monocytes and granulocytes. A case of P. vivax malaria in a patient with increased osmotically resistant erythrocytes illustrates the potential of the instrument to detect intraerythrocytic parasites with pigment. However, in most malaria-patients with normal red cell osmotic resistance the observed phenomena seem rather to represent intraleukocytic pigment. This can remain in the circulation of clinically and parasitologically cured individuals and thus may not indicate acute infection. While the instrument can indicate those patients who have been infected a diagnosis of acute malaria must be established independently.