Diversity, host switching and evolution of Plasmodium vivax infecting African great apes

Abstract

Plasmodium vivax is considered to be absent from Central and West Africa because of the protective effect of Duffy negativity. However, there are reports of persons returning from these areas infected with this parasite and observations suggesting the existence of transmission. Among the possible explanations for this apparent paradox, the existence of a zoonotic reservoir has been proposed. May great apes be this reservoir? We analyze the mitochondrial and nuclear genetic diversity of P. vivax parasites isolated from great apes in Africa and compare it to parasites isolated from travelers returning from these regions of Africa, as well as to human isolates distributed all over the world. We show that the P. vivax sequences from parasites of great apes form a clade genetically distinct from the parasites circulating in humans. We show that this clade's parasites can be infectious to humans by describing the case of a traveler returning from the Central African Republic infected with one of them. The relationship between this P. vivax clade in great apes and the human isolates is discussed.emergence | transfer | malaria | sylvatic | origin

Selective sweep suggests transcriptional regulation may underlie Plasmodium vivax resilience to malaria control measures in Cambodia

“…Evidence has shown that both species of malaria are significantly less diverse than primate malarias and likely have undergone genetic bottlenecks associated with host switching and emergence out of Africa, likely less than 10,000 y ago (63,(68)(69)(70)(71)(72). As these species have emerged from the bottleneck, they likely have undergone both sustained and recent selection.…”

Ape malaria transmission and potential for ape-to-human transfers in Africa

“…Several authors have speculated about the possibility that apes could be a source of new Plasmodium infections for humans and vice versa, providing a mosquito species could act as bridge between these different host species (5,17). Several recent studies have indeed reported transfers of Plasmodium from apes to humans or humans to apes in certain conditions, but the mosquitoes involved in these transfers were never identified (4,7,9,33).…”

“…Similarly, ancient reciprocal transplant experiments of Laverania parasites between humans and apes (mostly chimpanzees) failed to produce infections (5). On the contrary, for parasites of the subgenus Plasmodium, like P. vivax or P. malariae, transfers were documented in natural populations (2,4,7) or during experimental infections (5). All this suggests therefore a strong host specificity of the Laverania parasites.…”

Wild African great apes as natural hosts of malaria parasites: current knowledge and research perspectives

“…Since wild chimpanzees in West and Central Africa were confirmed hosts of P. vivax-like strains, it was hypothesised that wild apes could act as a natural reservoir (Rayner et al, 2011), thereby explaining the occasional infection of travellers despite the low prevalence of P. vivax in the human populations of these regions (Broderick et al, 2015;Culleton et al, 2008;Gautret et al, 2001;Mühlberger et al, 2004;Skarbinski et al, 2006). Moreover, a P. vivax-like parasite isolated from a traveller coming back from a Central African forest was recently shown to cluster with the AGA isolates outside of the human lineage, confirming the occurrence of cross-species transmissions (Liu et al, 2014;Prugnolle et al, 2013). This is supported by the fact that P. vivax-like parasite DNA was found in an anthropophilic mosquito species, Anopheles moucheti .…”