title: Clinical characteristics of severe community-acquired pneumonia among younger patients: an analysis of 18 years at a community hospital.
abstract: Unlike elderly patients with community-acquired pneumonia whose outcomes are markedly affected by their background characteristics, it appears that the severity of the infection itself contributes to outcomes in younger patients with community-acquired pneumonia. In order to identify clinical characteristics of severe community-acquired pneumonia in younger patients under 60 years old, among such cases prospectively collected at our hospital over a period of 18 years, those meeting the criteria for severe community-acquired pneumonia, as defined in the Infectious Diseases Society of America/American Thoracic Society Guidelines for community-acquired pneumonia, were retrospectively examined and compared to elderly patients with severe community-acquired pneumonia. Younger patients with severe pneumonia accounted for 12.9% of younger hospitalized patients. Although the incidence of severe pneumonia in younger patients was lower than that in elderly patients, its severity may be underestimated by severity assessment based on the conventional guidelines. Thus, attention is required. While Streptococcus pneumoniae and Legionella species were important causative pathogens, atypical pathogens and viruses were also frequently detected. There were only 11 deaths over a period of 18 years. Based on multivariate analysis, the risk factors for aggravation of community-acquired pneumonia among younger patients were age 50 years or older, diabetes mellitus, chronic liver disease, and Legionella pneumonia. Although the mortality rate from community-acquired pneumonia is extremely low in previously healthy younger patients, outcomes might be poor for patients with underlying diseases and those with rapid progression. Multimodal treatments including respiratory management may be appropriate.
authors.affiliation: Dept. of Respiratory Medicine, Kurashiki Central Hospital, Kurashiki, Japan. Electronic address: ishidat@kchnet.or.jp.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ishida
authors.affiliation: Dept. of Respiratory Medicine, Kurashiki Central Hospital, Kurashiki, Japan.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Tachibana
authors.affiliation: Dept. of Respiratory Medicine, Kurashiki Central Hospital, Kurashiki, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Ito
authors.affiliation: Dept. of Respiratory Medicine, Kurashiki Central Hospital, Kurashiki, Japan.
authors.forename: Maki
authors.initials: M
authors.lastname: Tanaka
authors.affiliation: Dept. of Respiratory Medicine, Kurashiki Central Hospital, Kurashiki, Japan.
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Tokioka
authors.affiliation: Dept. of Respiratory Medicine, Kurashiki Central Hospital, Kurashiki, Japan.
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Furuta
authors.affiliation: Dept. of Respiratory Medicine, Kurashiki Central Hospital, Kurashiki, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Nishiyama
authors.affiliation: Dept. of Respiratory Medicine, Kurashiki Central Hospital, Kurashiki, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ikeda
authors.affiliation: Dept. of Respiratory Medicine, Kurashiki Central Hospital, Kurashiki, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Niwa
authors.affiliation: Dept. of Respiratory Medicine, Kurashiki Central Hospital, Kurashiki, Japan.
authors.forename: Hiroshige
authors.initials: H
authors.lastname: Yoshioka
authors.affiliation: Dept. of Respiratory Medicine, Kurashiki Central Hospital, Kurashiki, Japan.
authors.forename: Machiko
authors.initials: M
authors.lastname: Arita
authors.affiliation: Dept. of Respiratory Medicine, Kurashiki Central Hospital, Kurashiki, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Hashimoto
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D017714:Community-Acquired Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D006764:Hospitals, Community; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D000900:Anti-Bacterial Agents
keywords: Mortality; Severe community-acquired pneumonia; Severity criteria; Younger patients