Ecology of malaria infections in western lowland gorillas inhabiting Dzanga Sangha Protected Areas, Central African Republic

Abstract

African great apes are susceptible to infections with several species of Plasmodium, including the predecessor of Plasmodium falciparum. Little is known about the ecology of these pathogens in gorillas. A total of 131 gorilla fecal samples were collected from Dzanga-Sangha Protected Areas to study the diversity and prevalence of Plasmodium species. The effects of sex and age as factors influencing levels of infection with Plasmodium in habituated gorilla groups were assessed. Ninety-five human blood samples from the same locality were also analysed to test for cross-transmission between humans and gorillas. According to a cytB PCR assay 32% of gorilla's fecal samples and 43·1% human individuals were infected with Plasmodium spp. All Laverania species, Plasmodium vivax, and for the first time Plasmodium ovale were identified from gorilla samples. Plasmodium praefalciparum was present only from habituated individuals and P. falciparum was detected from human samples. Although few P. vivax and P. ovale sequences were obtained from gorillas, the evidence for cross-species transmission between humans and gorillas requires more in depth analysis. No association was found between malaria infection and sex, however, younger individuals aged ≤6 years were more susceptible. Switching between two different Plasmodium spp. was observed in three individuals. Prolonged monitoring of Plasmodium infection during various seasons and recording behavioural data is necessary to draw a precise picture about the infection dynamics.

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

“…Faecal detection rates of Plasmodium infection were found to be higher in younger individuals of P. t. verus (De Nys et al, 2013) and G. g. gorilla (Mapua et al, 2015) as well as in pregnant females of P. t. verus (De Nys et al, 2014). This probably reflects changes in the frequency of new infections and/or in parasite densities induced by variation in susceptibility to these parasites due to age and pregnancy status.…”

“…P. praefalciparum, P. adleri and P. blacklocki (Liu et al, 2010(Liu et al, , 2016Prugnolle et al, 2010), and two non-Laverania species, i.e. P. vivax- (Liu et al, 2014) and ovale-like parasites (Mapua et al, 2015) (Fig. 1b).…”

Molecular interactions governing host-specificity of blood stage malaria parasites

“…Finally, most primate species (e.g., the ape Laverania [5]) appear to be either incapable of crossing species boundaries or do so inefficiently. Although P. malariae and P. ovale parasites have also been isolated from African great apes [5,78,79], the directionality of transmission (i.e., ape-to-human or human-to-ape) currently remains unclear.…”

No impact of strongylid infections on the detection of Plasmodium spp. in faeces of western lowland gorillas and eastern chimpanzees

“…Since 2007 we have been systematically surveying parasite infections of humans, western lowland gorillas and other wildlife inhabiting Dzanga Sangha Protected Areas (DSPA), Central African Republic (CAR), as part of an ongoing health-monitoring programme [5, 9]. Previous research has shown that both gorillas in DSPA and chimpanzees in Kalinzu Forest Reserve (KFR), Uganda were infected with strongylid nematodes [9], (Hasegawa and Pafčo, unpublished data) and with malaria parasites Plasmodium spp.…”

“…Previously, studies in NHPs focused on the genetic diversity of Plasmodium spp. [3] and/or ecological aspects [5], no study has investigated co-infections with malaria and other pathogens.…”