Please confirm topic selection

Are you sure you want to trigger topic in your Anconeus AI algorithm?

Please confirm action

You are done for today with this topic.

Would you like to start learning session with this topic items scheduled for future?

Updated: Dec 27 2021


  • Snapshot
    • A 50-year-old man presents to the emergency room for prolonged fever, shortness of breath, and chest pain. He is admitted for heart failure and suspected endocarditis. A cardiac echocardiogram shows vegetation on the valves. The initial blood cultures are negative. Upon further investigation, he works at a leather supplier and often visits farms to evaluate the cattle. He is treated for a suspected zoonotic endocarditis with doxycycline and hydrochloroquine.
  • Introduction
    • Classification
      • Coxiella burnetii
        • obligate intracellular gram-negative bacteria
        • Legionellales order
        • causes Q fever and culture-negative bacterial endocarditis
        • transmitted from farm animals (sheep, goat, and cattle amniotic fluid) via inhalation of aerosolized spores even at low doses
        • no arthropod vector
    • Prevention
      • Q fever vaccine is available in Australia for those with high occupational risk
  • Epidemiology
    • Incidence
      • found worldwide
    • Risk factors
      • exposure to farm animals
      • occupational exposure to animal products (e.g., animal hides)
      • immunosuppression
    • Pathogenesis
      • C. burnetii is able to replicate in phagocytic vacuoles in low pH environments
      • can survive oxidative and osmotic stress
      • can survive in the environment for years
  • Presentation
    • Symptoms
      • fever and headaches
      • chronic infection
        • weight loss
        • night sweats
      • acute infection
        • pneumonia
          • cough
          • sore throat
    • Physical exam
      • acute infection
        • pneumonia
          • rhonchi on lung exam
          • shortness of breath
      • chronic infection
        • endocarditis
          • heart failure
          • shortness of breath
        • vascular infection
          • abdominal pain
          • infected aneurysm
          • vascular rupture
        • osteomyelitis
          • tenosynovitis
          • tenderness at the site of infection
        • hepatitis
          • jaundice
  • Imaging
    • Chest radiography
      • indication
        • suspected pneumonia from acute Q fever
      • findings
        • lobar opacities or patchy infiltrates
    • Echocardiography
      • indication
        • suspected endocarditis from chronic Q fever
      • findings
        • vegetation on valves, most commonly mitral valve
  • Studies
    • Labs
      • blood cultures are usually negative
      • transaminitis
      • elevated erythrocyte sedimentation rate or C-reactive protein
      • confirmatory testing
        • detection of immunoglobulin G (IgG) on serology
        • detection of DNA on polymerase chain reaction
    • Making the diagnosis
      • based on clinical presentation and laboratory studies
      • suspect Q fever in cases of culture-negative endocarditis
  • Differential
    • Tularemia
      • distinguishing factor
        • typically presents with a maculopapular rash that may ulcerate
    • Bacterial endocarditis
      • distinguishing factors
        • blood cultures are usually positive
        • other culture-negative endocarditis to consider are
          • Bartonella spp
          • HACEK (Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, and Kingella)
  • Treatment
    • Medical
      • doxycycline
        • indication
          • all patients
      • hydroxychloroquine
        • indication
          • chronic Q fever
          • given with doxycycline
      • trimethoprim/sulfamethoxazole
        • indication
          • for pregnant women
        • outcome
          • may reduce fetal death
  • Complications
    • Adverse fetal outcomes in pregnant women
  • Prognosis
    • May have prolonged course if untreated
    • Most cases resolve with treatment
1 of 0
Private Note

Attach Treatment Poll
Treatment poll is required to gain more useful feedback from members.
Please enter Question Text
Please enter at least 2 unique options
Please enter at least 2 unique options
Please enter at least 2 unique options