Summary
Definition
History and exam
Key diagnostic factors
- cough
- influenza-like illness
- dyspnea
- fever
- decreased breath sounds
- tachypnea
Other diagnostic factors
- vomiting, diarrhea
- altered mental status
Risk factors
- environmental exposure to Asian lineage A(H7N9) virus
- close contact with infected humans
- laboratory work with A(H7N9) virus
Diagnostic tests
1st tests to order
- CBC with differential
- LFTs
- chest x-ray
- pulse oximetry
- sputum Gram stain
- sputum and blood bacterial culture
- reverse transcription polymerase chain reaction (RT-PCR)
Tests to consider
- viral culture
Treatment algorithm
close contact of confirmed or probable case
suspected or probable or confirmed infection
Contributors
Authors
Jake Dunning, BSc (Hons), MBBS, MRCP, PhD
Consultant and Honorary Clinical Associate Professor in Infectious Diseases and High Consequence Infectious Diseases
Royal Free London NHS Foundation Trust
London
UK
Disclosures
JD declares that he has no competing interests.
Timothy M. Uyeki, MD, MPH, MPP
Chief Medical Officer
Influenza Division
National Center for Immunization and Respiratory Diseases
Centers for Disease Control and Prevention
Atlanta
GA
Disclosures
TMU was a member of the Guideline Development Group for the World Health Organization Standard Guidance for the Clinical Management of Severe Influenza in 2017-2019, with recommendations posted by the World Health Organization in 2022. TMU was a co-chair for the Clinical Practice Guidelines by the Infectious Diseases Society of America: 2018 update on diagnosis, treatment, chemoprophylaxis, and institutional outbreak management of seasonal influenza, which published in 2019. He is also the author of several papers cited in this topic.
Acknowledgements
Dr Jake Dunning and Dr Timothy M. Uyeki would like to gratefully acknowledge Dr Justin R. Ortiz, a previous contributor to this topic.
Disclosures
JRO is a member of the International Council on Adult Immunization and the scientific community for the Global Influenza Hospitalization Surveillance Network.
Peer reviewers
Rob Fowler, MDCM, MSc
Senior Scientist
Sunnybrook Health Sciences Centre
Toronto
Ontario
Canada
Disclosures
RF declares that he has no competing interests.
Nelson Lee, MD, FRCP(Lond.), FRCP(Edin.)
Professor
Division of Infectious Diseases
Faculty of Medicine and Dentistry
University of Alberta
Edmonton
Alberta
Canada
Disclosures
NL declares that he has no competing interests.
Michael Ison, MD, MS
Professor
Division of Infectious Diseases
Division of Organ Transplantation
Northwestern University Feinberg School of Medicine
Chicago
IL
Disclosures
MI declares that he received research support, paid to Northwestern University, from Beckman Coulter, Chimerix, and Gilead; is a paid consultant for Celltrion, Chimerix, Farmark, Genentech/Roche, Toyama/MediVector, Seqirus, and Shionogi; and is a member of the DSMB for GlaxoSmithKline and Shionogi.
Differentials
- Coronavirus disease 2019 (COVID-19)
- Community-acquired pneumonia
- Atypical pneumonia
More DifferentialsGuidelines
- Interim guidance on testing and specimen collection for patients with suspected infection with novel influenza A viruses with the potential to cause severe disease in humans
- Avian influenza: guidance, data and analysis
More GuidelinesPatient information
Flu
Pneumonia
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