title: Long-term detection of seasonal influenza RNA in faeces and intestine.
abstract: Some cases of seasonal influenza virus (human influenza A virus (IAV)/human influenza B virus (IBV)) are associated with abdominal symptoms. Although virus RNA has been detected in faeces, intestinal infection has not been clearly demonstrated. We aimed to provide evidence that IAV/IBV infects the human intestine. This prospective observational study measured virus RNA in faecal and sputum samples from 22 patients infected with IAV/IBV (19 IAV positive and three IBV positive). Nineteen patients were included in the analysis and were assigned to faecal IAV-positive and -negative groups. Virus kinetics were examined in faecal samples from an IAV-infected patient (patient 1) and an IBV-infected patient (patient 2). Finally, intestinal tissue from an IAV-diagnosed patient who developed haemorrhagic colitis and underwent colonoscopy was examined for the presence of replicating IAV (patient 3). Virus RNA was detected in faecal samples from 8/22 IAV/IBV-infected patients (36.4%). Diarrhoea occurred significantly more often in the faecal IAV-positive group (p 0.002). In patients 1 and 2, virus RNA became undetectable in sputum on days 7 and 10 after infection, respectively, but was detected in faeces for a further 2 weeks. Virus mRNA and antigens were detected in intestinal tissues (mucosal epithelium of the sigmoid colon) from patient 3. These findings suggest that IAV/IBV infects within the intestinal tract; thus, the human intestine may be an additional target organ for IAV/IBV infection.
authors.affiliation: Department of Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan; Department of Infectious Diseases, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Hirose
authors.affiliation: Department of Infectious Diseases, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan. Electronic address: daidoji@koto.kpu-m.ac.jp.
authors.forename: T
authors.initials: T
authors.lastname: Daidoji
authors.affiliation: Department of Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Naito
authors.affiliation: Department of Infectious Diseases, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Watanabe
authors.affiliation: Department of Infectious Diseases, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan; Department of Viral Infection, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Arai
authors.affiliation: Department of Gastroenterology and General Medicine, Reimeikai Kitade Hospital, Wakayama, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Oda
authors.affiliation: Department of Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Konishi
authors.affiliation: Department of Medical Education and General Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yamawaki
authors.affiliation: Department of Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Itoh
authors.affiliation: Department of Infectious Diseases, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nakaya
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D001706:Biopsy; D002460:Cell Line; D002648:Child; D002675:Child, Preschool; D020685:Colonoscopes; D005243:Feces / Q000821:virology*; D005260:Female; D006801:Humans; D007223:Infant; D009980:Influenza A virus / Q000235:genetics; D007251:Influenza, Human / Q000175:diagnosis / Q000453:epidemiology* / Q000821:virology*; D029524:Betainfluenzavirus / Q000235:genetics; D007422:Intestines / Q000473:pathology / Q000821:virology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012367:RNA, Viral; D012621:Seasons; D019562:Viral Load; D055815:Young Adult
chemical_list: D012367:RNA, Viral
keywords: Colitis; Colonoscopy; Faeces; Influenza; Intestine