Avian influenza A(H7N9) virus infection

Last reviewed: 18 Apr 2022
Last updated: 19 Dec 2019

Summary

Definition

History and exam

Key diagnostic factors

  • cough
  • typical influenza signs and symptoms
  • dyspnoea
  • fever
  • decreased breath sounds
  • tachypnoea
More key diagnostic factors

Other diagnostic factors

  • vomiting, diarrhoea
  • altered mental status
Other diagnostic factors

Risk factors

  • environmental exposure to Asian lineage A(H7N9) virus
  • close contact with infected humans
  • laboratory work with A(H7N9) virus
More risk factors

Diagnostic investigations

1st investigations to order

  • FBC with differential
  • liver function tests (alkaline phosphatase, hepatic aminotransferases, bilirubin)
  • CXR
  • pulse oximetry
  • sputum Gram stain
  • sputum and blood bacterial culture
  • reverse transcription polymerase chain reaction (RT-PCR) of respiratory specimens for Asian lineage A(H7N9) virus and influenza A and B viruses
More 1st investigations to order

Investigations to consider

  • viral culture of respiratory specimens
More investigations to consider

Emerging tests

  • serological testing for A(H7N9)-specific antibody for retrospective diagnosis

Treatment algorithm

INITIAL

unprotected exposed healthcare workers and close contacts of suspected/confirmed case

suspected infection

ACUTE

confirmed illness

Contributors

Authors

Jake Dunning, BSc (Hons), MBBS, MRCP, PhD

Consultant in Infectious Diseases and General (Internal) Medicine

Tuberculosis; Acute Respiratory, Gastrointestinal, Emerging and Zoonotic Infections; and Travel Health (TARGET) Division

National Infection Service

Public Health England

London

UK

Disclosures

JD declares that he has no competing interests.

Justin R. Ortiz, MD, MS

Associate Professor of Medicine

Center for Vaccine Development and Global Health

University of Maryland School of Medicine

Baltimore

MD

Disclosures

JRO is a member of the International Council on Adult Immunization and the scientific community for the Global Influenza Hospitalization Surveillance Network.

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 is a member of the Guideline Development Group for the World Health Organization Standard Guidance for the Clinical Management of Severe Influenza. TMU is 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.

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 Differentials
  • Guidelines

    • Avian influenza: guidance, data and analysis
    • WHO portal for avian and other zoonotic influenza
    More Guidelines
  • Patient leaflets

    Flu

    More Patient leaflets
  • padlock-lockedLog in or subscribe to access all of BMJ Best Practice

Use of this content is subject to our disclaimer