title: A genetic analysis of Trichuris trichiura and Trichuris suis from Ecuador.
abstract: BACKGROUND
  Since the nematodes Trichuris trichiura and T. suis are morphologically indistinguishable, genetic analysis is required to assess epidemiological cross-over between people and pigs. This study aimed to clarify the transmission biology of trichuriasis in Ecuador.
  
  
  RESULTS
  Adult Trichuris worms were collected during a parasitological survey of 132 people and 46 pigs in Esmeraldas Province, Ecuador. Morphometric analysis of 49 pig worms and 64 human worms revealed significant variation. In discriminant analysis morphometric characteristics correctly classified male worms according to host species. In PCR-RFLP analysis of the ribosomal Internal Transcribed Spacer (ITS-2) and 18S DNA (59 pig worms and 82 human worms), nearly all Trichuris exhibited expected restriction patterns. However, two pig-derived worms showed a "heterozygous-type" ITS-2 pattern, with one also having a "heterozygous-type" 18S pattern. Phylogenetic analysis of the mitochondrial large ribosomal subunit partitioned worms by host species. Notably, some Ecuadorian T. suis clustered with porcine Trichuris from USA and Denmark and some with Chinese T. suis.
  
  
  CONCLUSIONS
  This is the first study in Latin America to genetically analyse Trichuris parasites. Although T. trichiura does not appear to be zoonotic in Ecuador, there is evidence of genetic exchange between T. trichiura and T. suis warranting more detailed genetic sampling.
authors.affiliation: Department of Production and Population Health, Royal Veterinary College, Hawkshead Lane, Hatfield, Herts, AL9 7TA, UK. hayley.meekums@hotmail.co.uk.
authors.forename: Hayley
authors.initials: H
authors.lastname: Meekums
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlaegevej 100, Frederiksberg C, DK-1870, Denmark. mfahmy@sci.cu.edu.eg.|Zoology Department, Faculty of Science, Cairo University, Giza, 12613, Egypt. mfahmy@sci.cu.edu.eg.
authors.forename: Mohamed B F
authors.initials: MB
authors.lastname: Hawash
authors.affiliation: Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK. s1349885@sms.ed.ac.uk.|Institute of Immunology and Infection Research, Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, King's Buildings, Ashworth Laboratories, Charlotte Auerbach Road, Edinburgh, EH9 3FL, UK. s1349885@sms.ed.ac.uk.
authors.forename: Alexandra M
authors.initials: AM
authors.lastname: Sparks
authors.affiliation: Laboratorio de Investigaciones FEPIS, Quinindé, Esmeraldas Province, Ecuador. goviv1@yahoo.com.
authors.forename: Yisela
authors.initials: Y
authors.lastname: Oviedo
authors.affiliation: Laboratorio de Investigaciones FEPIS, Quinindé, Esmeraldas Province, Ecuador. carloscarlossandoval@hotmail.com.
authors.forename: Carlos
authors.initials: C
authors.lastname: Sandoval
authors.affiliation: Laboratorio de Investigaciones FEPIS, Quinindé, Esmeraldas Province, Ecuador. marthachico6@yahoo.es.
authors.forename: Martha E
authors.initials: ME
authors.lastname: Chico
authors.affiliation: Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK. Russell.Stothard@lstmed.ac.uk.
authors.forename: J Russell
authors.initials: JR
authors.lastname: Stothard
authors.affiliation: Laboratorio de Investigaciones FEPIS, Quinindé, Esmeraldas Province, Ecuador. pcooper@sgul.ac.uk.|Centro de Investigaciónen Enfermedades Infecciosas, Pontificia Universidad Católica del Ecuador, Quito, Ecuador. pcooper@sgul.ac.uk.|Institute of Infection and Immunity, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK. pcooper@sgul.ac.uk.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Cooper
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlaegevej 100, Frederiksberg C, DK-1870, Denmark. pn@sund.ku.dk.
authors.forename: Peter
authors.initials: P
authors.lastname: Nejsum
authors.affiliation: Department of Production and Population Health, Royal Veterinary College, Hawkshead Lane, Hatfield, Herts, AL9 7TA, UK. mbetson@rvc.ac.uk.
authors.forename: Martha
authors.initials: M
authors.lastname: Betson
mesh_terms: D015766:Albendazole / Q000627:therapeutic use; D000818:Animals; D000871:Anthelmintics / Q000627:therapeutic use; D004484:Ecuador / Q000453:epidemiology; D006801:Humans; D010802:Phylogeny; D011716:Pyrantel Pamoate / Q000627:therapeutic use; D012424:Rural Population; D014257:Trichuriasis / Q000453:epidemiology / Q000469:parasitology / Q000635:transmission / Q000662:veterinary*; D014258:Trichuris / Q000235:genetics*; D015047:Zoonoses
chemical_list: D000871:Anthelmintics; D011716:Pyrantel Pamoate; D015766:Albendazole