Increased Trends of P. vivax in Sub-Saharan Africa: What Does it Mean for Malaria Elimination?

Abstract

Plasmodium vivax being the most geographically spread Plasmodium species is considered sparsely distributed in sub-Saharan Africa (sSA) while P. falciparum is the most prevalent species in this region. Thus, control strategies in sSA have been disproportionately targeted towards falciparum malaria. Nevertheless, with the use of more sensitive malaria diagnostic platforms, there are more reports of P. vivax and other non-falciparum malaria in sSA. In addition, P. vivax is presumed benign, however there are new findings of severe cases recorded from P. vivax single or mixed infection with other Plasmodium species. Besides, the extended dormant period (lasting for weeks or months) is a challenge for achieving effective cure for vivax infections. Although, chloroquine has been proscribed for treatment P. falciparum, it still remains the drug of choice for P. vivax in most Asian countries where it is predominant. In sSA, artemisinin combination-based therapies (ACTs) are used for treatment of falciparum malaria and, it is probable that the use of ACT could be enhancing adaptive selection for P. vivax in the face of its increasing prevalence in the population. Hence, understanding epidemiological and biological factors, and data that could be contributing to the observed steady increase in P. vivax prevalence in sSA is important. In this chapter, we discuss the mechanisms for invasion of red blood cells, trends in increasing prevalence of vivax malaria, diagnostic tools, and the public health implications of P. vivax and P. falciparum co-endemicity in Africa.