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Last reviewed: 17 Mar 2025
Last updated: 29 Apr 2021

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors
  • illness in other family members

Other diagnostic factors

  • fever
  • malaise
  • headache
  • cough
  • sore throat
  • rales
  • tachypnoea
  • pharyngitis
  • conjunctivitis
  • hepatomegaly
  • confusion
  • tachycardia
  • splenomegaly

Risk factors

  • exposure to infected birds and mammals
  • young children
  • older adults
  • immunocompromised

Diagnostic investigations

1st investigations to order

  • white blood cell count with differential
  • liver function tests
  • polymerase chain reaction (PCR)
  • chest x-ray

Treatment algorithm

Contributors

Authors

Deborah Dean, MD, MPH
Deborah Dean

Director

Children’s Global Health Initiative

Senior Scientist

Center for Immunobiology and Vaccine Development

Professor of Medicine

University of California at San Francisco and Berkeley

Faculty, the UC Berkeley - UCSF Graduate Program in Bioengineering

Children's Hospital Oakland Research Institute

Oakland

CA

Disclosures

DD is an author of some references cited in this topic.

Peer reviewers

Servaas Morre, PhD

Head of Laboratory of Immunogenetics

VU University Medical Center

Department of Pathology

Laboratory of Immunogenetics

Amsterdam

Netherlands

Disclosures

SM declares that he has no competing interests.

William A. Petri, Jr., MD, PhD, FACP

Chief and Professor of Medicine

Division of Infectious Diseases and International Health

University of Virginia Health System

Charlottesville

VA

Disclosures

WAP declares that he has no competing interests.

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