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Community-acquired pneumonia distinguished from influenza infection based on clinical signs and symptoms during a novel (swine) influenza A/H1N1 pandemic

Abstract

Aims

The numbers of patients with influenza-like illnesses increase during influenza outbreaks. A study was undertaken to distinguish community-acquired pneumonia (CAP) from influenza based on clinical signs and symptoms.

Methods

This retrospective study investigated patients with positive results in the rapid influenza antigen test and those diagnosed with CAP during an influenza A/H1N1 pandemic. Significant factors for predicting risk for CAP within 48 hrs from onset and at diagnosis were selected by multiple regression analysis.

Results

Within 48 hrs of onset and at diagnosis, age, sputum and coarse crackles significantly increased the risk of CAP whereas sick contact, sore throat, and rhinorrhoea significantly decreased the risk of CAP. Duration of illness, sputum, dyspnoea, chest pain, and coarse crackles also significantly increased the risk of CAP at diagnosis.

Conclusions

CAP differed somewhat from influenza even within 48 hrs of onset and the differences became even more evident thereafter.

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Authors and Affiliations

Authors

Contributions

All authors clinically treated corresponding patients in this study. Nakanishi and Yoshimasa Yoshida reviewed all chest X-rays and clinical records.

Corresponding author

Correspondence to Masanori Nakanishi.

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Competing interests

The authors declare that they have no conflicts of interest in relation to this article.

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Cite this article

Nakanishi, M., Yoshida, Y., Takeda, N. et al. Community-acquired pneumonia distinguished from influenza infection based on clinical signs and symptoms during a novel (swine) influenza A/H1N1 pandemic. Prim Care Respir J 20, 421–426 (2011). https://doi.org/10.4104/pcrj.2011.00067

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  • DOI: https://doi.org/10.4104/pcrj.2011.00067

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