Plasmodium malariae: the persisting mysteries of a persistent parasite.

Plasmodium malariae , the quartan malaria parasite of man, is a neglected species. Advances in molecular detection techniques are revealing a much greater prevalence of this species than previously thought. There remain many mysteries surrounding its biology and epidemiology, including its true prevalence, and the nature of its interactions with coinfecting malaria species. We review some outstanding mysteries and dogmas concerning the biology and epidemiology of P. malariae. Plasmodium malariae is a 'neglected malaria parasite' in as much as the amount of research conducted on it pales into insignificance when compared to that pertaining to Plasmodium falciparum and Plasmodium vivax , its more notorious and pathogenic cousins. There has, however, been an increase in interest in this parasite over the past decade. Principally, this is because of the increasing use of sensitive molecular detection techniques that have revealed a wider than previously recorded prevalence in some regions (particularly in Africa), and high numbers of chronic, asymptomatic infections. [ABSTRACT FROM AUTHOR]