title: Ascariasis in Japan: is pig-derived Ascaris infecting humans?
abstract: Human ascariasis is caused by infection with the common roundworm Ascaris lumbricoides, although the pig roundworm Ascaris suum has also been reported to infect humans and develop into the adult stage. To elucidate whether pig-derived Ascaris infects humans in Japan, 9 Ascaris isolates obtained from Japanese patients and a further 9 Ascaris isolates of pig origin were analyzed to determine their internal transcribed spacer-1 sequences. Six of the 9 clinical isolates showed the Ascaris genotype which predominantly infects humans in endemic countries, while the other 3 clinical isolates and 9 pig-derived isolates showed the genotype predominant in pigs worldwide. These results suggest that at least some cases of human ascariasis in Japan are a result of infection with pig-derived Ascaris.
authors.affiliation: Department of Medical Zoology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan. arizonon@koto.kpu-m.ac.jp
authors.forename: Naoki
authors.initials: N
authors.lastname: Arizono
authors.forename: Yuta
authors.initials: Y
authors.lastname: Yoshimura
authors.forename: Naoki
authors.initials: N
authors.lastname: Tohzaka
authors.forename: Minoru
authors.initials: M
authors.lastname: Yamada
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Tegoshi
authors.forename: Kotaro
authors.initials: K
authors.lastname: Onishi
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Uchikawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001196:Ascariasis / Q000469:parasitology / Q000635:transmission* / Q000662:veterinary; D017165:Ascaris suum / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D018509:DNA, Helminth / Q000032:analysis / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000032:analysis / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics; D006801:Humans; D007564:Japan; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D017422:Sequence Analysis, DNA; D013552:Swine; D013553:Swine Diseases / Q000469:parasitology / Q000635:transmission; D055815:Young Adult; D015047:Zoonoses / Q000469:parasitology / Q000635:transmission
chemical_list: D018509:DNA, Helminth; D021903:DNA, Ribosomal Spacer; D003576:Electron Transport Complex IV