title: Cystic echinococcoses in Mongolia: molecular identification, serology and risk factors.
abstract: BACKGROUND
  Cystic echinococcosis (CE) is a globally distributed cestode zoonosis that causes hepatic cysts. Although Echinococcus granulosus sensu stricto (s.s.) is the major causative agent of CE worldwide, recent molecular epidemiological studies have revealed that E. canadensis is common in countries where camels are present. One such country is Mongolia.
  
  
  RESULTS
  Forty-three human hepatic CE cases that were confirmed histopathologically at the National Center of Pathology (NCP) in Ulaanbaatar (UB) were identified by analysis of mitochondrial cox 1 gene as being caused by either E. canadensis (n=31, 72.1%) or E. granulosus s.s. (n=12, 27.9%). The majority of the E. canadensis cases were strain G6/7 (29/31, 93.5%). Twenty three haplotypes were identified. Sixteen of 39 CE cases with data on age, sex and province of residence were citizens of UB (41.0%), with 13 of the 16 cases from UB caused by E. canadensis (G6/7) (81.3%). Among these 13 cases, nine were children (69.2%). All pediatric cases (n  =  18) were due to E. canadensis with 17 of the 18 cases (94.4%) due to strain G6/7. Serum samples were available for 31 of the 43 CE cases, with 22 (71.0%) samples positive by ELISA to recombinant Antigen B8/1 (rAgB). Nine of 10 CE cases caused by E. granulosus s.s. (90.0%) and 13 of 20 CE cases by E. canadensis (G6/7) (65.0%) were seropositive. The one CE case caused by E. canadensis (G10) was seronegative. CE cases caused by E. granulosus s.s. showed higher absorbance values (median value 1.131) than those caused by E. canadensis (G6/7) (median value 0.106) (p  =  0.0137).
  
  
  CONCLUSIONS
  The main species/strains in the study population were E. canadenis and E. granulossus s.s. with E. canadensis the predominant species identified in children. The reason why E. canadensis appears to be so common in children is unknown.
authors.affiliation: Department of Parasitology, Asahikawa Medical University, Asahikawa, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Ito
authors.affiliation: Department of Parasitology, Asahikawa Medical University, Asahikawa, Japan; Department of Medical Biology and Histology, School of Biomedicine, Health Sciences University of Mongolia, Ulaanbaatar, Mongolia.
authors.forename: Temuulen
authors.initials: T
authors.lastname: Dorjsuren
authors.affiliation: Department of Parasitology, Asahikawa Medical University, Asahikawa, Japan; National Center for Communicable Diseases, Ulaanbaatar, Mongolia.
authors.forename: Anu
authors.initials: A
authors.lastname: Davaasuren
authors.affiliation: Department of Parasitology, Asahikawa Medical University, Asahikawa, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Yanagida
authors.affiliation: Department of Parasitology, Asahikawa Medical University, Asahikawa, Japan.
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Sako
authors.affiliation: Department of Parasitology, Asahikawa Medical University, Asahikawa, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nakaya
authors.affiliation: Department of Parasitology, Asahikawa Medical University, Asahikawa, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Nakao
authors.affiliation: National Center of Pathology, Ulaanbaatar, Mongolia.
authors.forename: Oyun-Erdene
authors.initials: OE
authors.lastname: Bat-Ochir
authors.affiliation: National Center for Maternal and Child Health, Ulaanbaatar, Mongolia.
authors.forename: Tsendjav
authors.initials: T
authors.lastname: Ayushkhuu
authors.affiliation: Department of Surgery, State Central First Hospital, Ulaanbaatar, Mongolia.
authors.forename: Narantuya
authors.initials: N
authors.lastname: Bazarragchaa
authors.affiliation: Department of Surgery, State Central First Hospital, Ulaanbaatar, Mongolia.
authors.forename: Nyamkhuu
authors.initials: N
authors.lastname: Gonchigsengee
authors.affiliation: Department of Parasitology, Asahikawa Medical University, Asahikawa, Japan; Institute of Parasitic Diseases, Sichuan Centers for Disease Control and Prevention, Chengdu, China.
authors.forename: Tiaoying
authors.initials: T
authors.lastname: Li
authors.affiliation: Department of Medical Biology and Histology, School of Biomedicine, Health Sciences University of Mongolia, Ulaanbaatar, Mongolia.
authors.forename: Gurbadam
authors.initials: G
authors.lastname: Agvaandaram
authors.affiliation: Department of Parasitology, Asahikawa Medical University, Asahikawa, Japan; National Center for Communicable Diseases, Ulaanbaatar, Mongolia.
authors.forename: Abmed
authors.initials: A
authors.lastname: Davaajav
authors.affiliation: Department of Parasitology, Asahikawa Medical University, Asahikawa, Japan; Institute of Veterinary Medicine, Ulaanbaatar, Mongolia.
authors.forename: Chinchuluun
authors.initials: C
authors.lastname: Boldbaatar
authors.affiliation: Department of Parasitology, Asahikawa Medical University, Asahikawa, Japan; Mongolian Academy of Science, Ulaanbaatar, Mongolia.
authors.forename: Gantigmaa
authors.initials: G
authors.lastname: Chuluunbaatar
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D002648:Child; D002675:Child, Preschool; D004444:Echinococcosis, Hepatic / Q000175:diagnosis* / Q000453:epidemiology*; D004446:Echinococcus / Q000145:classification / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D003576:Electron Transport Complex IV / Q000235:genetics; D005260:Female; D006239:Haplotypes; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D008986:Mongolia / Q000453:epidemiology; D012307:Risk Factors; D017422:Sequence Analysis, DNA; D055815:Young Adult
chemical_list: D000909:Antibodies, Helminth; D003576:Electron Transport Complex IV