Do hypnozoites cause relapse in malaria?

Abstract

The concept that hypnozoites give rise to relapses in Plasmodium vivax and Plasmodium ovale malaria has become dogma. However, it is evident from particular contemporary research findings that hypnozoites are not necessarily the origin of all relapse-like recurrences of malaria caused by these parasites. This is the core opinion presented, and I discuss it fully. The hypnozoite theory of relapse needs to be re-evaluated in view of the recent, increased focus on P. vivax and liver stages of Plasmodium. Hypnozoites have also assumed a new significance because they might, by facilitating ongoing transmission, be a threat to the current (post-2007) goal of eliminating malaria globally. I have suggested some new research directions for finding putative nonhypnozoite sources of recurrent malaria.

Keywords: Plasmodium ovale; Plasmodium vivax; hypnozoite; malaria; primaquine; relapse.