title: Hidden population structure and cross-species transmission of whipworms (Trichuris sp.) in humans and non-human primates in Uganda.
abstract: BACKGROUND
  Whipworms (Trichuris sp.) are a globally distributed genus of parasitic helminths that infect a diversity of mammalian hosts. Molecular methods have successfully resolved porcine whipworm, Trichuris suis, from primate whipworm, T. trichiura. However, it remains unclear whether T. trichiura is a multi-host parasite capable of infecting a wide taxonomic breadth of primate hosts or a complex of host specific parasites that infect one or two closely related hosts.
  
  
  RESULTS
  We examined the phylogenetic structure of whipworms in a multi-species community of non-human primates and humans in Western Uganda, using both traditional microscopy and molecular methods. A newly developed nested polymerase chain reaction (PCR) method applied to non-invasively collected fecal samples detected Trichuris with 100% sensitivity and 97% specificity relative to microscopy. Infection rates varied significantly among host species, from 13.3% in chimpanzees (Pan troglodytes) to 88.9% in olive baboons (Papio anubis). Phylogenetic analyses based on nucleotide sequences of the Trichuris internal transcribed spacer regions 1 and 2 of ribosomal DNA revealed three co-circulating Trichuris groups. Notably, one group was detected only in humans, while another infected all screened host species, indicating that whipworms from this group are transmitted among wild primates and humans.
  
  
  CONCLUSIONS
  Our results suggest that the host range of Trichuris varies by taxonomic group, with some groups showing host specificity, and others showing host generality. In particular, one Trichuris taxon should be considered a multi-host pathogen that is capable of infecting wild primates and humans. This challenges past assumptions about the host specificity of this and similar helminth parasites and raises concerns about animal and human health.
authors.affiliation: Department of Biology, McGill University, Montreal, Quebec, Canada.
authors.forename: Ria R
authors.initials: RR
authors.lastname: Ghai
authors.affiliation: Department of Anthropology, University of Oregon, Eugene, Oregon, United States of America.
authors.forename: Noah D
authors.initials: ND
authors.lastname: Simons
authors.affiliation: Department of Anthropology and McGill School of Environment, Montreal, Quebec, Canada, and Wildlife Conservation Society, Bronx, New York, New York, United States of America; Makerere University Biological Field Station, Fort Portal, Uganda.
authors.forename: Colin A
authors.initials: CA
authors.lastname: Chapman
authors.affiliation: Makerere University Biological Field Station, Fort Portal, Uganda.
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Omeja
authors.affiliation: Department of Biology, McGill University, Montreal, Quebec, Canada.
authors.forename: T Jonathan
authors.initials: TJ
authors.lastname: Davies
authors.affiliation: Department of Anthropology, University of Oregon, Eugene, Oregon, United States of America; Institute for Ecology and Evolution, University of Oregon, Eugene, Oregon, United States of America.
authors.forename: Nelson
authors.initials: N
authors.lastname: Ting
authors.affiliation: Makerere University Biological Field Station, Fort Portal, Uganda; Department of Pathobiological Sciences and Global Health Institute, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Tony L
authors.initials: TL
authors.lastname: Goldberg
mesh_terms: D000818:Animals; D001483:Base Sequence; D058507:Host Specificity; D006801:Humans; D008969:Molecular Sequence Data; D002679:Pan troglodytes / Q000469:parasitology; D010215:Papio / Q000469:parasitology; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011323:Primates / Q000469:parasitology*; D014257:Trichuriasis / Q000469:parasitology* / Q000635:transmission / Q000662:veterinary; D014258:Trichuris / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D014454:Uganda