Influenza infection
Summary
Definition
History and exam
Key diagnostic factors
- winter season
- current influenza outbreak
- unvaccinated
- fever with cough
Other diagnostic factors
- sore throat
- cervical lymphadenopathy
- dyspnea
Risk factors
- age ≥65 years
- age 6-59 months
- chronic cardiovascular or respiratory conditions
- diabetes
- hemoglobinopathy
- immunocompromise
- chronic kidney disease (CKD)
- pregnancy
- caregivers and household contacts of high-risk groups
- healthcare workers
Diagnostic investigations
1st investigations to order
- clinical diagnosis
Investigations to consider
- viral culture
- direct immunofluorescent antibody staining
- reverse transcriptase-polymerase chain reaction
- serology
- enzyme immunoassay (EIA)
- rapid diagnostic tests
- chest x-ray
Treatment algorithm
exposure to infected individual(s) in at-risk population
adults
children
Contributors
Authors
Cristine Radojicic, MD
Staff Physician
Department of Pulmonary, Allergy and Critical Care
Cleveland Clinic
Cleveland
OH
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.
Differentials
- Coronavirus disease 2019 (COVID-19)
- Bacterial pneumonia
- Respiratory syncytial virus (RSV) infection
More DifferentialsGuidelines
- Recommended adult immunization schedule for ages 19 years or older, United States, 2022
- Recommended child and adolescent immunization schedule for ages 18 years or younger, United States, 2022
More GuidelinesPatient leaflets
Flu
Antibiotics: what you need to know
More Patient leaflets
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