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Influenza infection

Last reviewed: 9 Nov 2024
Last updated: 03 Apr 2024

Summary

Definition

History and exam

Key diagnostic factors

  • winter season
  • current influenza outbreak
  • unvaccinated
  • fever with cough
Full details

Other diagnostic factors

  • sore throat
  • cervical lymphadenopathy
  • dyspnea
Full details

Risk factors

  • age ≥65 years
  • age 6-59 months
  • chronic cardiovascular or respiratory conditions
  • diabetes
  • hemoglobinopathy
  • immunocompromised status
  • chronic kidney disease (CKD)
  • pregnancy
  • caregivers and household contacts of high-risk groups
  • healthcare workers
Full details

Diagnostic tests

1st tests to order

  • clinical diagnosis
Full details

Tests to consider

  • molecular assays
  • antigen detection tests
  • viral culture
  • serology
  • chest x-ray
Full details

Treatment algorithm

INITIAL

exposure to infected individual(s) in at-risk population

ACUTE

adults

children

Contributors

Authors

Kyle Eggleton, MBChB PhD FRNZCGP(Dist)

Associate Dean Rural

Department of General Practice and Primary Health Care

University of Auckland

Auckland

New Zealand

Disclosures

KE declares that he has no competing interests.

Rachel Roskvist, MBChB, FRNZCGP, MHSc

Senior Lecturer

Department of General Practice and Primary Health Care

University of Auckland

Auckland

New Zealand

Disclosures

RR declares that she has no competing interests.

Bruce Arroll, MBChB PhD FRNZCGP

Department of General Practice and Primary Health Care

University of Auckland

Auckland

New Zealand

Disclosures

BA declares that he has no competing interests.

Acknowledgements

Dr Kyle Eggleton, Dr Rachel Roskvist, and Professor Bruce Arroll would like to gratefully acknowledge Dr Cristine Radojicic, a previous contributor to this topic.

Disclosures

CR declares that she is on Advisory boards for CSL Behring and Speakers Bureau Biocryst.

Peer reviewers

Waleed Javaid, MD, FACP, FIDSA

Associate Professor

Medical Director of Infection Control

Infectious Disease

Department of Medicine

SUNY Upstate Medical University

Syracuse

NY

Disclosures

WJ declares that he has no competing interests.

Rachel L. Miller, MD, FAAAAI

Associate Professor of Clinical Medicine and Environmental Health Sciences

Columbia University College of Physicians and Surgeons

New York

NY

Disclosures

RLM declares that she has no competing interests.

Mark Sands, MD, FAAAAI

Chief

SUNY Buffalo School of Medicine

Division Allergy and Immunology

Buffalo

NY

Disclosures

MS declares that he has no competing interests.

An De Sutter, MD, PhD

Associate Professor

Department of General Practice and Primary Health Care

Ghent University

Ghent

Belgium

Disclosures

ADS declares that she has no competing interests.

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