Q fever
Background
- Described in 1937: occupational disease of abattoir workers (manage animals before and after slaughtering process) and dairy farmers
- Caused by Coxiella burnetii
- Obligate intracellular bacteria morphologically similar to Rickettsia
- Reservoirs include cattle, goat, sheep, and ticks (Dermacentor andersoni)
- CDC: category B biologic warfare agent due to its inhaled infectivity
- Worldwide disease
Clinical Features
- Symptoms usually develop within 2-3 weeks, although up to half of those infected may not show symptoms
- high fevers (up to 104-105°F)
- severe headache
- general malaise
- myalgias
- chills/sweats
- non-productive cough
- nausea/vomiting
- diarrhea
- abdominal pain
- chest pain
- Complications include pneumonia, granulomatous hepatitis (inflammation of the liver), myocarditis (inflammation of the heart tissue), and central nervous system complications.
- Endocarditis is the major form of chronic disease
- Infection in pregnancy is more likely to be asymptomatic, but often results in chronic Q fever and obstetrical complications
Differential Diagnosis
Fever in traveler
- Normal causes of acute fever!
- Malaria
- Dengue
- Leptospirosis
- Typhoid fever
- Typhus
- Viral hemorrhagic fevers
- Chikungunya
- Yellow fever
- Rift valley fever
- Q fever
- Amebiasis
- Zika virus
Workup
- CBC, Complete Metabolic Panel – Liver enzymes usually elevated 2-10 times normal
- Blood Cultures
- CXR
Management
- Doxycycline
- Adults: 100 mg BID
- Children < 45 kg: 2.2 mg/kg BID
- Patients should be treated for at least 3 days after the fever subsides and until there is evidence of clinical improvement. Standard duration of treatment is 2-3 weeks.
Disposition
See Also
External Links
Sources
- http://www.cdc.gov/qfever/
- Rosen’s Emergency Medicine 8th Edition
- www.uptodate.com
- http://www.ncbi.nlm.nih.gov/pubmed/16168313