Tuberc Respir Dis.  2017 Oct;80(4):392-400. 10.4046/trd.2016.0015.

Incidence and Risk Factors of Pneumonia in Hospitalized Patients with Seasonal Influenza A or B

• Chu S
• Park SJ
• Koo SM
• Kim YK
• Kim KU
• Uh ST
• Kim TH
• Park S

• KMID: 2420582
• DOI: http://doi.org/10.4046/trd.2016.0015

Abstract

BACKGROUND
Most patients with influenza recover spontaneously or following treatment with an anti-viral agent, but some patients experience pneumonia requiring hospitalization. We conducted a retrospective review to determine the incidence and risk factors of pneumonia in hospitalized patients with influenza A or B.
METHODS
A total of 213 patients aged 18 years or older and hospitalized with influenza between January 2012 and January 2015 were included in this study. A reverse-transcriptase polymerase chain reaction assay was used to detect the influenza A or B virus in the patients' sputum samples. We collected demographic and laboratory data, combined coexisting diseases, and radiologic findings.
RESULTS
The incidence of pneumonia was higher in patients in the influenza A group compared to those in the influenza B group (68.6% vs. 56.9%), but this difference was not statistically significant. The presence of underlying respiratory disease was significantly associated with pneumonia in the influenza A group (adjusted odds ratio [OR], 3.975; 95% confidence interval [CI], 1.312-12.043; p=0.015). In the influenza B group, the white blood cell count (adjusted OR, 1.413; 95% CI, 1.053-1.896; p=0.021), platelet count (adjusted OR, 0.988; 95% CI, 0.978-0.999; p=0.027), and existence of an underlying medical disease (adjusted OR, 15.858; 95% CI, 1.757-143.088; p=0.014) were all significantly associated with pneumonia in multivariate analyses.
CONCLUSION
The incidence of pneumonia was 65.7% in hospitalized patients with influenza A or B. The risk factors of pneumonia differed in hospitalized patients with influenza A or B.

Keyword

Pneumonia; Influenza; Risk Factors; Comorbidity

MeSH Terms

Comorbidity
Herpesvirus 1, Cercopithecine
Hospitalization
Humans
Incidence*
Influenza, Human*
Leukocyte Count
Multivariate Analysis
Odds Ratio
Platelet Count
Pneumonia*
Polymerase Chain Reaction
Retrospective Studies
Risk Factors*
Seasons*
Sputum

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