title: Etiology of community-acquired pneumonia in hospitalized patients: a 3-year prospective study in Japan.
abstract: OBJECTIVE
  To compare the etiology of community-acquired pneumonia in Japan and Western countries, the causative pathogens were prospectively investigated in patients requiring hospitalization.
  
  
  METHODS
  Prospective study over a 3-year period.
  
  
  METHODS
  A community general hospital in Japan.
  
  
  METHODS
  Three hundred twenty-six episodes of community-acquired pneumonia in 318 patients admitted to the hospital between July 1994 and June 1997.
  
  
  METHODS
  The microbiological diagnosis was based on the results of quantitative sputum culture, blood culture, and other invasive procedures, including transthoracic needle aspiration or bronchoscopic examination. Serologic tests for Mycoplasma pneumoniae, Chlamydia spp, Legionella spp, and viruses were also routinely performed.
  
  
  RESULTS
  Causative pathogens were identified in 199 episodes (61%). Streptococcus pneumoniae was the most common pathogen (23%), followed by Haemophilus influenzae (7.4%), M pneumoniae (4.9%), and Klebsiella pneumoniae (4.3%). The Streptococcus milleri group and Chlamydia pneumoniae were detected in 3.7 and 3.4% of the episodes, respectively. Pneumonia due to Legionella spp was recognized in only two patients.
  
  
  CONCLUSIONS
  The etiology of community-acquired pneumonia in Japan did not differ markedly when compared with that of Western countries except for the low incidence of Legionella pneumonia. C pneumoniae and the S milleri group, which are emerging or newly recognized pathogens, were also significant causative microorganisms.
authors.affiliation: Department of Internal Medicine, Kurashiki Central Hospital, Okayama, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ishida
authors.forename: T
authors.initials: T
authors.lastname: Hashimoto
authors.forename: M
authors.initials: M
authors.lastname: Arita
authors.forename: I
authors.initials: I
authors.lastname: Ito
authors.forename: M
authors.initials: M
authors.lastname: Osawa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016993:Chlamydophila pneumoniae / Q000302:isolation & purification; D017714:Community-Acquired Infections / Q000382:microbiology*; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000382:microbiology*; D011446:Prospective Studies; D013296:Streptococcus pneumoniae / Q000302:isolation & purification