title: Etiological agents of lower respiratory tract infections in Japanese children.
abstract: To investigate the etiology of pediatric community-acquired pneumonia and bronchitis, we conducted a prospective, population-based study covering the total population < 15 years of age in 16 municipalities in Hokkaido, Japan, during the period of April 2000 to March 2001. Chest radiographs were available for all cases (n = 921; 398 as pneumonia and 523 as bronchitis) and paired sera for serologic assays were available for more than half of the cases. The following specimens were also collected: nasopharyngeal swabs for viral, bacteriological, mycoplasmal and chlamydial studies, blood for serology and blood culture. The children were then followed-up on days 3, 7 and 14. Specific infecting organisms were identified in a total of 853 (92.6%) out of 921 patients (398 cases of pneumonia and 523 cases of bronchitis) including 205 with mixed infection as follows: Mycoplasma pneumoniae, 252 (274%) patients; respiratory syncytial (RS) virus, 188 (20.4%); influenza A virus, 110 (11.9%); Streptococcus pneumoniae, 95 (10.3%); Haemophilus influenzae, 90 (9.8%); Haemophilus parainfluenzae, 35 (3.8%); Staphylococcus aureus, 29 (3.1%); adenovirus, 27 (2.9%); Moraxella catarrhalis, 12 (1.3%); Pseudomonas aeruginosa , 7 (0.8%); Chlamydia pneumoniae, 6 (0.7%); and other agents, 2 (0.2%). Mycoplasma infections were seen even in patients less than 5 years and RS and influenza A virus infections in patients more than 5 years of age. The importance of M. pneumoniae and RS virus in the etiology of lower respiratory infections in Japanese children was confirmed.
authors.affiliation: Research Group of Hokkaido for Pediatric Respiratory Tract Infections, Department of Pediatrics, Sapporo Medical University School of Medicine, Japan. numazaki@sapmed.ac.jp
authors.forename: Kei
authors.initials: K
authors.lastname: Numazaki
authors.forename: Shunzo
authors.initials: S
authors.lastname: Chiba
authors.forename: Masao
authors.initials: M
authors.lastname: Umetsu
authors.forename: Toru
authors.initials: T
authors.lastname: Tanaka
authors.forename: Hideatsu
authors.initials: H
authors.lastname: Yoshimura
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kuniya
authors.forename: Junichi
authors.initials: J
authors.lastname: Miura
authors.forename: Noriaki
authors.initials: N
authors.lastname: Adachi
authors.forename: Susumu
authors.initials: S
authors.lastname: Ukae
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Mori
authors.forename: Daisuke
authors.initials: D
authors.lastname: Ueda
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Hotsubo
authors.forename: Toshiya
authors.initials: T
authors.lastname: Sato
mesh_terms: D001991:Bronchitis / Q000453:epidemiology / Q000382:microbiology / Q000821:virology; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology* / Q000821:virology*; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D018410:Pneumonia, Bacterial / Q000453:epidemiology; D011024:Pneumonia, Viral / Q000453:epidemiology; D011446:Prospective Studies; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000382:microbiology* / Q000821:virology*