artemisinin; bone marrow; control; drug evasion; elimination; eradication; hypnozoite; hypnozoites; life cycle; liver; malaria; Plasmodium vivax; primaquine; recrudescence; recurrence; relapse; spleen

We talk about asymptomatic, submicroscopic plasmodial infections as potentially being a threat to the elimination of malaria. This is, of course, partly because such infections are not normally treated; especially not in rural endemic areas where laboratory facilities are limited. An aggravation of the situation is when parasitaemias are so low that they cannot be detected by molecular diagnosis (where available) either. But obstacles to elimination are probably even greater than has been realized.