title: Prospective multicenter study of the causative organisms of community-acquired pneumonia in adults in Japan.
abstract: Although a wide variety of recognized pathogens causes community-acquired pneumonia, the precise etiology in Japan remains unknown. We prospectively investigated the etiology in 232 patients with community-acquired pneumonia who visited 20 community-general hospitals. New diagnostic methods, using polymerase chain reaction (PCR) assays and urinary antigen tests were employed, in addition to conventional methods. The frequency of identification of causative pathogens was high (73.3%), and the leading organism was Streptococcus pneumoniae (24.6%), followed by Haemophilus influenzae (18.5%), viruses (16.4%), Chlamydia pneumoniae (6.5%), Mycoplasma pneumoniae (5.2%), and Legionella spp. (3.9%). S. pneumoniae and M. pneumoniae were the most prevalent pathogens in younger patients, and S. pneumoniae and H. influenzae were the most prevalent in elderly patients. Multiple or mixed infections were found in 25.9% of all patients and in 35.3% with a causal diagnosis. The results have important practical implications for the initial treatment of adult patients with community-acquired pneumonia.
authors.affiliation: First Department of Internal Medicine, Faculty of Medicine, University of the Ryukyus, Okinawa 903-0125, Japan. saito@isahaya.jrc.or.jp
authors.forename: Atsushi
authors.initials: A
authors.lastname: Saito
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kohno
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Matsushima
authors.forename: Akira
authors.initials: A
authors.lastname: Watanabe
authors.forename: Kotaro
authors.initials: K
authors.lastname: Oizumi
authors.forename: Keizo
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Oda
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017714:Community-Acquired Infections / Q000382:microbiology*; D005260:Female; D006090:Gram-Negative Bacteria / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000382:microbiology*; D011024:Pneumonia, Viral / Q000821:virology; D011446:Prospective Studies; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*