Q Fever Clinical Presentation

Author: Kelley Struble, DO; Chief Editor: Burke A Cunha, MD more...

Updated: Jan 25, 2012

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History
Physical Examination
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History

Q fever is a protean disease that lacks a distinct clinical presentation. Almost 50% of patients are asymptomatic. Common presentations vary geographically. For example, in the Basque region of northern Spain, pneumonia is a common finding, whereas in southern Spain, hepatitis predominates.

The primary factor leading to the identification of Q fever is the epidemiologic circumstance: a history of exposure, particularly occupational exposure, exposure to parturient animals or their newborn, or tick bites.

Most common symptoms include fever

Acute Q fever

Sixty percent of patients with Q fever are asymptomatic. The incubation period varies from 2 to 6 weeks (range, 14-39 d; average, 20 d). The 3 main clinical presentations are as follows^{[2, 15, 19]}:

A self-limited, influenzalike febrile illness (up to 40°C) (88-100%) of abrupt onset, which is often accompanied by headache (68-98%) (typically retrobulbar), myalgia (47-69%) (arthralgia is uncommon), chills (68-88%), fatigue (97-100%), and sweats (31-98%); the temperature returns to normal within 5-14 days
Pneumonia (predominant in North America), usually mild in nature (crackles auscultated in 50% of cases) or as an incidental radiographic finding; when there is respiratory involvement, patients have a dry, nonproductive cough (24-90%), dyspnea, and pleuritic chest pain; this condition is rarely fulminant but occasionally progresses to acute respiratory distress syndrome (ARDS)
Hepatitis (predominant in Europe), usually with mild elevation of transaminases (2-3 times the reference range) and may be associated with antismooth muscle, antiphospholipid, or antinuclear antibodies; jaundice and acute gastrointestinal (GI) symptoms (nausea and vomiting, diarrhea [rare], right upper quadrant abdominal pain) are rare; manifestations resolve within 2-3 weeks.

Cardiovascular and neurologic manifestations develop in approximately 1% of patients and include pericarditis, myocarditis, and meningoencephalitis. A dissociation between heart rate and temperature occurs in one third of cases, some patients with acute Q fever pericarditis report chest pain, patients with myocarditis may experience palpitations, chest pain, or dyspnea. The 3 major neurologic syndromes of Q fever are meningoencephalitis or encephalitis, meningitis, and myelitis and peripheral neuropathy. Other neurologic symptoms may include headache, confusion, and neck stiffness.

Dermatologic manifestations in the form of erythema nodosum or other nonspecific exanthemas, maculopapular rash, or diffuse punctiform pruritic rash may also be associated with acute disease. Rash is not a typical feature of Q fever, but skin manifestations have been reported in up to 20% of French patients.^[19]

Obstetric manifestations include spontaneous abortion. Rare presentations have included thyroiditis, mediastinal lymphadenopathy, pancreatitis, mesenteric panniculitis, epididymitis, orchitis, priapism, inappropriate secretion of antidiuretic hormone (SIADH), optic neuritis, Guillain-Barré syndrome, and extrapyramidal neurologic disease.

Chronic Q fever

Among patients with acute infection, 0.2-1.4% may develop chronic infection, but few data are available regarding this. Chronic infection (defined as infection lasting longer than 6 months) may not manifest until months or even years after acute infection.^{[2, 15, 19]}

Endocarditis with negative culture findings and seropositivity (culture positivity and seropositivity or culture negativity and seronegativity are relatively uncommon) is the main clinical presentation of chronic Q fever, usually occurring in patients with preexisting cardiac disease including valve defects, rheumatic heart disease, and prosthetic valves. Patients in immunocompromised states (eg, due to acquired immunodeficiency syndrome [AIDS], renal failure, hematologic cancer [including lymphoma], and long-term corticosteroid use) are also susceptible. Patients may present with heart failure or nonspecific symptoms, including low-grade fever, fatigue, chills, arthralgia, dyspnea, rash from septic thromboembolism, and night sweats.

Other systemic manifestations include the following:

Vascular (infections of aneurysms, grafts, prostheses)
Osteoarticular (osteomyelitis,^[5]coxitis, spondylodiskitis, arthritis, septic arthritis, no associated host factors in children, immunocompromise or prosthetic joints in adults)
Obstetric (spontaneous abortion, premature labor [likely due to placentitis])
Hepatic (chronic hepatitis [usually associated with endocarditis])
Neurologic (mononeuritis, optic neuritis^[5])
Pulmonary (interstitial fibrosis, pseudotumor)
Renal (glomerulonephritis)

Chronic fatigue syndrome has also been described in approximately 10% of patients, more than 6 months following acute Q fever. In addition, C burnetii could be added to the organisms involved in TORCH syndrome (toxoplasmosis, other infections, rubella, cytomegalovirus infection, and herpes simplex).

Physical Examination

Specific physical findings may be absent in acute Q fever. When present, physical findings vary with the clinical presentation. In chronic Q fever, findings consistent with endocarditis and hepatitis are more frequently found. Aseptic meningitis/encephalitis occurs in approximately 1% of acute and chronic Q fever cases.

Acute Q fever

Signs of acute Q fever may include the following:

Pneumonia: High-grade fever and nonspecific crackles, rales, rhonchi, or wheezing; dry cough, pleuritic chest pain, dyspnea, tachypnea; less frequently, signs of consolidation or pleural effusion
Isolated fever: Fever may be low grade but is usually as high as 40°C
Hepatitis: Hepatomegaly or, in rare cases, jaundice; fever, malaise, right upper quadrant abdominal pain may be present
Meningeal signs, pericardial rub (pericarditis), and signs of heart failure may be present; tachycardia, an irregular pulse, and a gallop rhythm (myocarditis)
Meningitis or encephalitis (rare, approximately 1%): Severe headache, stiff neck, fever
Nonspecific exanthemas (20%), most commonly a maculopapular rash on the trunk; erythema nodosum has also been described

Chronic Q fever

Endocarditis is the most common presentation of chronic disease and manifests as low-grade fever (or no fever), augmentation of a known heart murmur, signs of heart failure, hepatosplenomegaly and splenomegaly (approximately 50%), jaundice (occasional), clubbing, arterial emboli (approximated 33%), vegetations on any valve (although aortic and prosthetic valves are favored), and purpuric rash (approximately 20%).^[2]The aortic and mitral valves are more often involved.

Proceed to Differential Diagnoses

Contributor Information and Disclosures

Author

Kelley Struble, DO Fellow, Department of Infectious Diseases, University of Oklahoma College of Medicine

Disclosure: Nothing to disclose.

Coauthor(s)

Alexandre Lacasse, MD, MSc Internal Medicine Faculty, Assistant Director, Medicine Clinic, Infectious Disease Consultant, St Mary's Health Center

Alexandre Lacasse, MD, MSc is a member of the following medical societies: American College of Physicians, American Medical Association, Association of Program Directors in Internal Medicine, Infectious Diseases Society of America, and Society for Healthcare Epidemiology of America

Disclosure: Nothing to disclose.

Kerry O Cleveland, MD Associate Professor of Medicine, University of Tennessee College of Medicine; Consulting Staff, Department of Internal Medicine, Division of Infectious Diseases, Methodist Healthcare of Memphis

Kerry O Cleveland, MD is a member of the following medical societies: American College of Physicians, Infectious Diseases Society of America, and Society for Healthcare Epidemiology of America

Disclosure: Nothing to disclose.

Hari Polenakovik, MD Associate Professor of Medicine, Wright State University, Boonshoft School of Medicine

Hari Polenakovik, MD is a member of the following medical societies: Alpha Omega Alpha, American College of Physicians, American Society for Microbiology, European Society of Clinical Microbiology and Infectious Diseases, Infectious Diseases Society of America, and Society for Healthcare Epidemiology of America

Disclosure: Nothing to disclose.

Annie Ruest, MD, FRCPC Consultant Physician in Infectious Diseases and Medical Microbiology, CHUQ-Hôtel-Dieu de Québec, Departments of Medicine and Medical Biology, Laval University Faculty of Medicine, Canada

Annie Ruest, MD, FRCPC is a member of the following medical societies: Canadian Infectious Disease Society and Royal College of Physicians and Surgeons of Canada

Disclosure: Nothing to disclose.

Christian P Sinave, MD Associate Professor, Department of Medical Microbiology and Infectious Diseases, University of Sherbrooke Faculty of Medicine, Canada

Christian P Sinave, MD is a member of the following medical societies: American Society for Microbiology and Canadian Infectious Disease Society

Disclosure: Nothing to disclose.

Chief Editor

Burke A Cunha, MD Professor of Medicine, State University of New York School of Medicine at Stony Brook; Chief, Infectious Disease Division, Winthrop-University Hospital

Burke A Cunha, MD is a member of the following medical societies: American College of Chest Physicians, American College of Physicians, and Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Additional Contributors

Leslie L Barton, MD Professor Emerita of Pediatrics, University of Arizona College of Medicine

Leslie L Barton, MD is a member of the following medical societies: American Academy of Pediatrics, Association of Pediatric Program Directors, Infectious Diseases Society of America, and Pediatric Infectious Diseases Society