Coxiella burnetii infection is a notifiable condition in the US and some other countries.
People whose occupations put them at high risk of infection include abattoir workers, meat handlers, farmers, veterinarians, laboratory personnel, and military personnel.
Symptoms and complications correspond to either an acute infection or persistent focalized infections.
Infection during pregnancy may be associated with severe obstetric and fetal complications and endocarditis in the mother.
Acute infection can be treated with a short course of doxycycline, but persistent focalized infections require long-term therapy with doxycycline plus hydroxychloroquine. Surgical resection of infected vascular tissue or prosthetic material may also be required.
A zoonotic disease caused by the gram-negative, obligate, intracellular bacterium Coxiella burnetii. Many species of mammals, birds, and ticks are reservoirs of the bacterium, and the disease is spread globally through close contact with wild or domestic animals, especially their products of parturition, and also their urine, feces, or milk. However, C burnetii small cell variant (pseudospores) can spread by air up to 10 kilometers from the source of infection so that exposure history is frequently lacking. Symptoms and complications are different between acute infection (i.e., a self-limited febrile illness with varying degrees of pneumonia and hepatitis) and persistent focalized infections (e.g., endocarditis, vascular infection, osteoarticular infection, lymphadenitis). Infection during pregnancy has a specific clinical presentation (mostly asymptomatic), and may result in obstetric and fetal complications. Commonly known as Q fever.
BMJ talk medicine podcast. Coxiella burnetii infection: your questions answered by Dr Matthieu Million Opens in new window
History and exam
Key diagnostic factors
- abrupt onset of high fever
- flu-like illness
- severe headache
- inspiratory crackles, rhonchi, or wheezing
Other diagnostic factors
- pleuritic chest pain
- chronic fatigue
- signs of endocarditis or vascular infection (persistent focalized infection)
- other signs of persistent focalized infection
- other signs of acute infection
- exposure to infected animals
- occupational exposure
- travel or residency in endemic areas
- male sex
- age 30 to 70 years
- preexisting cardiac disease
- preexisting vasculopathy
1st investigations to order
- indirect immunofluorescence assay (IFA)
- polymerase chain reaction (PCR)
- activated partial thromboplastin time (aPTT)
- IgG anticardiolipin (aCL) antibodies
Investigations to consider
- cerebrospinal fluid cell count and differential
- cerebrospinal fluid protein
- cerebrospinal fluid glucose
- 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
- fluorescence in situ hybridization (FISH)
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
Joshua Hartzell, MD, MS-HPEd, FACP, FIDSA
Division of Infectious Diseases
Uniformed Services University of the Health Sciences
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.
Dr Joshua Hartzell would like to gratefully acknowledge Dr Matthieu Million, Professor Didier Raoult, and Dr Nilmarie Guzman, previous contributors to this topic.
MM and DR are authors of several references cited in this topic. NG declares that she has no competing interests.
Ron Behrens, MD, FRCP
Consultant in Tropical and Travel Medicine
Hospitals for Tropical Diseases
London School of Hygiene and Tropical Medicine
RB has provided expert testimony on behalf of the Crown, to the courts in the UK, on Q fever.
Jennifer McQuiston, DVM, MS, DACVPM
Rickettsial Zoonoses Branch
National Center for Zoonotic Vectorborne and Enteric Diseases
Centers for Disease Control and Prevention
JM declares that she has no competing interests.
Dimitrios Chatzidimitriou, MD, PhD
National Influenza Center
Second Department of Microbiology
Aristotle University of Thessaloniki Medical School
DC declares that he has no competing interests.
- Legionella infection
- Viral hepatitis
- CDC health information for international travel: Q fever
- CDNA national guidelines for public health units: Q fever
FluMore Patient leaflets
- Log in or subscribe to access all of BMJ Best Practice
Use of this content is subject to our disclaimer