title: Community-acquired pneumonia distinguished from  influenza infection based on clinical signs and symptoms  during a novel (swine) influenza A/H1N1 pandemic.
abstract: OBJECTIVE
  The numbers of patients with influenza-like illnesses increase during influenza outbreaks. A study was undertaken to distinguish  community-acquired pneumonia (CAP) from influenza based on clinical signs and symptoms.
  
  
  METHODS
  This retrospective study investigated patients with positive results in the rapid influenza antigen test and those diagnosed with  CAP during an influenza A/H1N1 pandemic. Significant factors for predicting risk for CAP within 48 hrs from onset and at diagnosis were  selected by multiple regression analysis.
  
  
  RESULTS
  Within 48 hrs of onset and at diagnosis, age and coarse crackles significantly increased the risk of CAP whereas sick contact, sore  throat, and rhinorrhoea significantly decreased the risk of CAP. Duration of illness, sputum, dyspnoea, chest pain, and coarse crackles also  significantly increased the risk of CAP at diagnosis.
  
  
  CONCLUSIONS
  CAP differed somewhat from influenza even within 48 hrs of onset and the differences became even more evident  thereafter.
authors.affiliation: Department of Respiratory Medicine, Shinseikai Toyama Hospital, Imizu, Japan. mnakanishi@nifty.ne.jp
authors.forename: Masanori
authors.initials: M
authors.lastname: Nakanishi
authors.forename: Yishimasa
authors.initials: Y
authors.lastname: Yoshida
authors.forename: Nobuya
authors.initials: N
authors.lastname: Takeda
authors.forename: Hirohumi
authors.initials: H
authors.lastname: Hirana
authors.forename: Takahiro
authors.initials: T
authors.lastname: Horita
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Shimizu
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Hiratani
authors.forename: Shigeo
authors.initials: S
authors.lastname: Toyoda
authors.forename: Takayuki
authors.initials: T
authors.lastname: Matsumura
authors.forename: Eiji
authors.initials: E
authors.lastname: Shinno
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hutamura
authors.forename: Masanari
authors.initials: M
authors.lastname: Ota
authors.forename: Toshoki
authors.initials: T
authors.lastname: Natazuka
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000956:Antigens, Viral / Q000097:blood; D017714:Community-Acquired Infections / Q000175:diagnosis; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D007251:Influenza, Human / Q000175:diagnosis* / Q000453:epidemiology*; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D058873:Pandemics; D011014:Pneumonia / Q000175:diagnosis* / Q000453:epidemiology* / Q000382:microbiology; D012044:Regression Analysis; D012189:Retrospective Studies; D013183:Sputum / Q000382:microbiology; D055815:Young Adult
chemical_list: D000956:Antigens, Viral