Is serology helpful in the diagnosis of malaria?

Malaria is arguably the most important parasitic disease of man, and falciparum malaria the most dangerous. More than 1·6 billion of the world's population live in malaria endemic areas¹. The increased availability of international air travel has made some endemic areas popular tourist resorts. In addition, immigrants to developed countries whose immunity has waned over the years may acquire malaria when they make a return visit to their country of origin². As a result there are up to 2000 new cases of malaria reported each year in the United Kingdom, which represents more than half of all cases imported into Europe^1,2. This has meant that malaria is no longer a rare or exotic disease, but one which every clinical laboratory will meet regularly and be required to diagnose. The examination of stained thick and thin blood films for the presence of malaria parasites is the mainstay of laboratory diagnosis. It combines a sensitivity and specificity unmatched by currently available serological techniques. Thus for the present and the immediate future conventional parasitological techniques will remain the investigation of choice. However, serology does have a part to play. This article will briefly outline human serological responses to malaria parasites which are useful for diagnosis, the techniques available, and the indications for their use in the clinical laboratory.