Authors: Martha Powell, Future Science Group
Malaria parasites, which have been reported in wild chimps and gorillas, have not previously been detected in bonobos. However, a new study has conducted a more extensive survey of these chimps, uncovering endemic malaria in the eastern-most section of their range and presenting evidence of a new malaria species.
The team, led by Beatrice Hahn (University of Pennsylvania, PA, USA), studies ape relatives of human pathogens, with the aim of gaining greater insight into these diseases. Previously (in 2010) the group discovered that gorillas were the origin of the human malaria parasite Plasmodium falciparum.
In this study, published recently in Nature Communications, they hoped to discover more about whether malaria parasites are present in wild bonobo populations, as Hahn explained: “Not finding any evidence of malaria in wild bonobos just didn’t make sense, given that captive bonobos are susceptible to this infection. We look for biological loopholes to potentially exploit the life history of these pathogens to better understand how they cross over to humans.”
The researchers used a sensitive assay, which allowed them to gather genetic information about malaria parasites from fecal samples gathered from forest floor, overall testing 1556 samples from 11 field sites across Africa.
The team discovered that bonobos are susceptible to wide variety of malaria species, including a previously unreported Laverania species that appears to be specific to bonobos, termed Plasmodium lomamiensis. However, they noted that natural infection was only detected in the eastern-most part of the bonobo range, therefore appearing to be geographically restricted.
Co-first author, Weimin Liu (University of Pennsylvania) commented: “For now, the geographic restriction of bonobo Plasmodium infection remains a mystery.”
The other first author, Scott Sherrill (University of Pennsylvania), added: “We have yet to identify the causes. We looked at what plants bonobos eat and what types of bacteria make up their gut microbiome, but these could not explain the absence of Plasmodium from most of the bonobo sites. From this, we suspect that factors that influence parasite transmission are involved.”
The team state that it is important to understand more about ape parasites, what factors affect their host-specificity and distribution, in addition to gathering information on whether there are circumstances under which any of them could cross the species barrier to humans.
Sources: Liu W, Sherill-Mix A, Learn GH et al. Wild bonobos host geographically restricted malaria parasites including a putative new Laverania species. Nat Comms. doi:10.1038/s41467-017-01798-5 (2017); www.eurekalert.org/emb_releases/2017-11/uops-psi112017.php