Genetic evidence for the role of non-human primates as reservoir hosts for human schistosomiasis

Abstract

Background Schistosomiasis is a chronic parasitic disease, that affects over 207 million people and causes over 200,000 deaths annually, mainly in sub-Saharan Africa. Although many health measures have been carried out to limit parasite transmission, significant numbers of nonhuman primates such as Chlorocebus aethiops (Ch. aethiops) (vervet) and Papio anubis (baboon) are infected with S. mansoni, notably in Ethiopia, where they are expected to have potentially significant implications for transmission and control efforts. Objective The objective of this study was to assess and compare the genetic diversity and population structure of S. mansoni isolates from human and non-human primates free-ranging in close proximity to villages in selected endemic areas of Ethiopia. Methods A cross-sectional study was conducted in three transmission sites: Bochesa, Kime and Fincha. A total of 2,356 S. mansoni miracidia were directly isolated from fecal specimens of 104 hosts (i.e. 60 human hosts and 44 non-human primates). We performed DNA extraction and PCR amplification using fourteen microsatellite loci. Results At population scale we showed strong genetic structure between the three sample sites. At the definitive host scale, we observed that host factors can shape the genetic composition of parasite infra-populations. First, in male patients, we observed a positive link between parasite genetic diversity and the age of the patients. Second, we observed a difference in PLOS NEGLECTED TROPICAL DISEASES

Population genetics of African Schistosoma species

“…One interesting outcome that differsbetween these two studies is that parasite genetic diversity increases only with male or female age Kebede et al (2020) or Faust et al (2019), respectively. This confirms that human behaviour can shape the parasite genetic composition but also,that acquired immunity does not seem to limit this diversity because no decline in genetic diversity was observed (Faust et al, 2019).…”

“…haematobiumfrom infected humans (Gower et al, 2011;Thiele et al, 2008;Van den Broeck et al, 2014). However, two recent studies showed that males have a higher schistosome genetic diversity than females (Faust et al, 2019;Kebede et al, 2020). This could reflect the differences in behaviour with young males having higher mobility and greater water contact compared to young females.…”

SARS‐CoV‐2 and wastewater: What does it mean for non‐human primates?

“…As novel human pathogens take hold in human populations there is a need to better understand the transmission routes and factors involved in anthropozoonoses that could endanger other species—an essential process for the creation of procedures and guidelines that will protect NHPs. Importantly, spillover events may also have future consequences since NHPs represent a potential deadly zoonotic reservoir for a variety of human pathogens (Devaux et al, 2019 ; Kebede et al, 2020 ). Therefore, the reduction of inter‐species transmission promotes a healthier community for both NHPs and humans.…”

Nucleic acid amplification techniques for the detection of Schistosoma mansoni infection in humans and the intermediate snail host: a structured review and meta-analysis of diagnostic accuracy

“…However, the definitive host is generally only humans except in schistosomiasis japonica and schistosomiasis mekongi that, in contrast to all other species, are zoonotic forms of the infection. S. mansoni infects sometimes also non-human primates (Kebede et al, 2020) and various rodent species (Gentile et al, 2011).…”