Etiology and factors contributing to the severity and mortality of community-acquired pneumonia.
OBJECTIVE
Community-acquired pneumonia (CAP) remains a major cause of death. No studies have reported the use of rapid influenza diagnostic tests (RIDT) for the etiological diagnosis, and the factors contributing to severity and mortality have not yet been fully investigated. The aim of this study was to review the etiologies of CAP using RIDT and to identify risk factors related to the severity and mortality of the disease.


METHODS
This retrospective study assessed these factors in hospitalized patients, with special emphasis on microbial etiology.


RESULTS
A total of 1,032 patients aged 63.9±18.3 years were studied, 66.2% of whom were men. Microbial identification was obtained in 57.0% of the cases. The most frequent causative microbial agents were Streptococcus pneumoniae, Mycoplasma pneumoniae and the influenza virus, and the second most frequent pathogens in the patients with severe CAP and the non-survivors were S. pneumoniae and the influenza virus. Age (≥65 years), chronic obstructive pulmonary disease, congestive heart failure, diabetes mellitus, dementia and Legionella spp. infection and polymicrobial infection were each found to be independent factors related to severity in the multivariate analysis, whereas "unidentified pathogen" was found to be an independent factor for non-severe CAP. Age (≥65 years), chronic pulmonary aspergillosis, post-lung cancer surgery and severe CAP were found to be independent factors for non-survival according to a multivariate analysis.


CONCLUSIONS
In addition to S. pneumoniae, the influenza virus was a frequent cause of CAP overall and a frequent causative pathogen in both severe cases of CAP and non-survivors. Legionella spp. infection and polymicrobial infection were found to be an independent factor for the severity of CAP along with advanced age and certain comorbidities. An advanced age, certain respiratory comorbidities and severe CAP were found to be important independent factors for the mortality of CAP.
Department of Respiratory Medicine, Saitama Cardiovascular and Respiratory Center, Japan. ishiguro.takashi@pref.saitama.lg.jp
Takashi
T
Ishiguro
Noboru
N
Takayanagi
Shozaburo
S
Yamaguchi
Hideaki
H
Yamakawa
Keitaro
K
Nakamoto
Yotaro
Y
Takaku
Yosuke
Y
Miyahara
Naho
N
Kagiyama
Kazuyoshi
K
Kurashima
Tsutomu
T
Yanagisawa
Yutaka
Y
Sugita
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017714:Community-Acquired Infections / Q000188:drug therapy / Q000209:etiology* / Q000401:mortality; D004791:Enzyme Inhibitors / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007251:Influenza, Human / Q000175:diagnosis / Q000209:etiology / Q000401:mortality; D007564:Japan / Q000453:epidemiology; D007877:Legionnaires' Disease / Q000209:etiology / Q000401:mortality; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009439:Neuraminidase / Q000037:antagonists & inhibitors; D011014:Pneumonia / Q000188:drug therapy / Q000209:etiology* / Q000401:mortality; D011019:Pneumonia, Mycoplasma / Q000209:etiology / Q000401:mortality; D011018:Pneumonia, Pneumococcal / Q000209:etiology / Q000401:mortality; D011024:Pneumonia, Viral / Q000209:etiology / Q000401:mortality; D012189:Retrospective Studies; D012307:Risk Factors
D004791:Enzyme Inhibitors; D009439:Neuraminidase