Attacking Plasmodium vivax

The clinical condition with infection by Plasmodium vivax worsens perniciously, more slowly and less dramatically than with infection by Plasmodium falciparum. The seemingly sluggish progress of the infection and its comparatively low levels of parasitemia lulled us into thinking it an intrinsically benign species. That false aegis fostered a deep neglect of P. vivax in research, clinical medicine, and public health throughout the second half of the 20th century. Today, we understand that poor access to limited health care results in delayed or inadequate therapy, and in such settings, P. vivax malaria often progresses to states of severe illness essentially similar to those of P. falciparum malaria. In the impoverished and often isolated rural tropics, endemic P. vivax threatens patients and populations because serious problems in the diagnosis, treatment, and control of that infection have not been solved. However, the long deferral of action in doing so may be considered nearly ended.

This extraordinary supplement of the American Journal of Tropical Medicine and Hygiene contains much of the evidence underpinning the World Health Organization's (WHO) Control and Elimination of Plasmodium vivax: A Technical Brief1 released in July 2015. That document had no predecessor, nor does this supplement. WHO guidance on this species had been either included in recommendations regarding malaria generically, or added as virtual afterthoughts in documents taking aim principally at guiding strategy and tactics against Plasmodium falciparum. The Technical Brief thus acknowledges both the importance of P. vivax as a global health problem and the requirement to adopt tactics and strategies rationally suited to the singular features of this species. That consideration explains the voluminous character of this supplement—P. vivax is a more complicated parasite and clinical/public health problem than P. falciparum.

Complexities relevant to recommendations in the Technical Brief are explained here in detail, with extensive referencing pointing out the relevant evidence. This supplement may thus be viewed as a resource for technical people engaging in the difficult business of researching or controlling and eliminating this pernicious and stubborn malaria problem.