title: New zoonotic cases of Onchocerca dewittei japonica (Nematoda: Onchocercidae) in Honshu, Japan.
abstract: BACKGROUND
  Zoonotic infections with Onchocerca species are uncommon, and to date only 25 clinical cases have been reported worldwide. In Japan, five previous zoonotic infections were concentrated in Oita, Kyushu (the southern island), with one previous case in Hiroshima in the western part of Honshu (the main island). The causative agent in Japan was identified as Onchocerca dewittei japonica Uni, Bain & Takaoka, 2001 from Japanese wild boars (Sus scrofa leucomystax Temminck, 1842). Here we report two infections caused by a female and male O. dewittei japonica, respectively, among residents of Hiroshima and Shimane Prefectures in the western part of Honshu.
  
  
  METHODS
  In both cases, nodules were surgically removed. The parasites in nodules were identified on the basis of their histopathological characteristics. Identification was confirmed by sequencing the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene from worms in the tissues used in the histological preparations.
  
  
  RESULTS
  Case 1 was a 61-year-old woman from Hiroshima Prefecture who complained of a painful subcutaneous nodule on the back of her right hand. The causative agent was identified as a female O. dewittei japonica owing to transverse ridges on the cuticle and molecular analysis. Case 2 was a 78-year-old woman from Shimane Prefecture who had a painful nodule in the left temporal region. Histopathological characteristics and cox1 sequencing of the worm indicated that the causative agent was a male O. dewittei japonica.
  
  
  CONCLUSIONS
  For Cases 1 and 2, we diagnosed the causative agents as a female and male O. dewittei japonica, respectively. These findings indicate the spread of a zoonosis caused by O. dewittei japonica in the western part of Honshu, where wild boars have recently extended their habitats because of decreased annual snowfall, unused rice fields and a decline in the number of hunters in Japan. The O. dewittei japonica infection rate among wild boars was reported as 78% in Shimane Prefecture, in the western part of Honshu. Therefore, in the near future, zoonotic onchocercosis is likely to occur in Honshu as well as Kyushu, where wild boars, blackfly vectors and humans share the same habitat.
authors.affiliation: Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia. unishigehiko@um.edu.my.|Department of Parasitology, Graduate School of Medicine, Osaka City University, Osaka, 545-8585, Japan. unishigehiko@um.edu.my.
authors.forename: Shigehiko
authors.initials: S
authors.lastname: Uni
authors.affiliation: Research Promotion Institute, Oita University, Oita, 879-5593, Japan. mfukuda@oita-u.ac.jp.
authors.forename: Masako
authors.initials: M
authors.lastname: Fukuda
authors.affiliation: Research Center for the Pacific Islands, Kagoshima University, Kagoshima, 890-8580, Japan. yotsuka@cpi.kagoshima-u.ac.jp.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Otsuka
authors.affiliation: Hiramatsu Orthopedic Clinic, Hiroshima, 730-0016, Japan. nobuo-h@hn-seikeigeka.jp.
authors.forename: Nobuo
authors.initials: N
authors.lastname: Hiramatsu
authors.affiliation: Hiroshima University Hospital, Hiroshima, 734-8551, Japan. yokobayashiken@gmail.com.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Yokobayashi
authors.affiliation: Hiroshima University Hospital, Hiroshima, 734-8551, Japan. peroshi0106@yahoo.co.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takahashi
authors.affiliation: Department of Dermatology, Faculty of Medicine, Shimane University, Shimane, 693-8501, Japan. smurata@med.shimane-u.ac.jp.
authors.forename: Susumu
authors.initials: S
authors.lastname: Murata
authors.affiliation: Department of Dermatology, Faculty of Medicine, Shimane University, Shimane, 693-8501, Japan. kusatake@med.shimane-u.ac.jp.
authors.forename: Kenji
authors.initials: K
authors.lastname: Kusatake
authors.affiliation: Department of Dermatology, Faculty of Medicine, Shimane University, Shimane, 693-8501, Japan. emorita@med.shimane-u.ac.jp.
authors.forename: Eishin
authors.initials: E
authors.lastname: Morita
authors.affiliation: Department of Infectious Diseases, Division of Parasitology, Faculty of Medicine, University of Miyazaki, Miyazaki, 889-1692, Japan. hikomaru@med.miyazaki-u.ac.jp.
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Maruyama
authors.affiliation: Department of Biology, Faculty of Medicine, Oita University, Oita, 879-5593, Japan. hasegawa@oita-u.ac.jp.
authors.forename: Hideo
authors.initials: H
authors.lastname: Hasegawa
authors.affiliation: Department of Environmental and Preventive Medicine, Faculty of Medicine, Shimane University, Shimane, 693-8501, Japan. shiwaku@jn.shimane-u.ac.jp.
authors.forename: Kuninori
authors.initials: K
authors.lastname: Shiwaku
authors.affiliation: Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia. rosliramli@um.edu.my.
authors.forename: Rosli
authors.initials: R
authors.lastname: Ramli
authors.affiliation: Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia. sofian@um.edu.my.
authors.forename: Mohd Sofian
authors.initials: MS
authors.lastname: Azirun
authors.affiliation: Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia. takaoka@oita-u.ac.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takaoka
mesh_terms: D000368:Aged; D000818:Animals; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009854:Onchocerca / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D009855:Onchocerciasis / Q000469:parasitology* / Q000635:transmission; D034421:Sus scrofa / Q000469:parasitology; D013552:Swine; D013553:Swine Diseases / Q000469:parasitology*; D015047:Zoonoses / Q000175:diagnosis / Q000469:parasitology* / Q000635:transmission