Summary
Definition
History and exam
Key diagnostic factors
- abrupt onset of high fever
- flu-like illness
- severe headache
- cough
- inspiratory crackles, rhonchi, or wheezing
- hepatomegaly
Other diagnostic factors
- exanthemas
- pleuritic chest pain
- seizures
- coma
- chronic fatigue
- signs of endocarditis or vascular infection (persistent focalized infection)
- other signs of persistent focalized infection
- other signs of acute infection
Risk factors
- exposure to infected animals
- occupational exposure
- travel or residency in endemic areas
- male sex
- age 30 to 70 years
- immunosuppression
- preexisting cardiac disease
- preexisting vasculopathy
- pregnancy
Diagnostic investigations
1st investigations to order
- indirect immunofluorescence assay (IFA)
- polymerase chain reaction (PCR)
- CBC
- CRP
- LFTs
- activated partial thromboplastin time (aPTT)
- IgG anticardiolipin (aCL) antibodies
Investigations to consider
- cerebrospinal fluid cell count and differential
- cerebrospinal fluid protein
- cerebrospinal fluid glucose
- CXR
- transthoracic echocardiography (TTE)
- transesophageal echocardiography (TEE)
- liver ultrasound
- abdominal CT scan or ultrasound
- chest CT
- brain CT
- 18F-fluorodeoxyglucose (FDG) PET/CT imaging
- lymph node biopsy
- immunohistochemistry
- fluorescence in situ hybridization (FISH)
Treatment algorithm
acute infection, nonpregnant, no severe immunodeficiency: at low risk of persistent focalized infection
acute infection, nonpregnant, no severe immunodeficiency: at high risk of persistent focalized infection
acute infection, nonpregnant, with severe immunodeficiency
acute infection, pregnant
suspected or confirmed persistent focalized infection, with no severe immunodeficiency
suspected or confirmed persistent focalized infection, with severe immunodeficiency
Contributors
Authors
Joshua Hartzell, MD, MS-HPEd, FACP, FIDSA
Division of Infectious Diseases
Uniformed Services University of the Health Sciences
Bethesda
MD
Disclosures
JH declares he has no competing interests. The opinions or assertions contained herein are the private ones of the reviewer and are not to be construed as official or reflecting the views of the Department of Defense, the Uniformed Services University of the Health Sciences, or any other agency of the US Government.
Acknowledgements
Dr Joshua Hartzell would like to gratefully acknowledge Dr Matthieu Million, Professor Didier Raoult, and Dr Nilmarie Guzman, previous contributors to this topic.
Disclosures
MM and DR are authors of several references cited in this topic. NG declares that she has no competing interests.
Peer reviewers
Ron Behrens, MD, FRCP
Consultant in Tropical and Travel Medicine
Hospitals for Tropical Diseases
Senior Lecturer
London School of Hygiene and Tropical Medicine
London
UK
Disclosures
RB has provided expert testimony on behalf of the Crown, to the courts in the UK, on Q fever.
Jennifer McQuiston, DVM, MS, DACVPM
Epidemiology Team
Rickettsial Zoonoses Branch
National Center for Zoonotic Vectorborne and Enteric Diseases
Centers for Disease Control and Prevention
Atlanta
GA
Disclosures
JM declares that she has no competing interests.
Dimitrios Chatzidimitriou, MD, PhD
Clinical Microbiologist
National Influenza Center
Second Department of Microbiology
Aristotle University of Thessaloniki Medical School
Thessaloniki
Greece
Disclosures
DC declares that he has no competing interests.
Differentials
- Legionella infection
- Tularemia
- Viral hepatitis
More DifferentialsGuidelines
- CDC health information for international travel: Q fever
- CDNA national guidelines for public health units: Q fever
More GuidelinesPatient leaflets
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