Tularemia

1. See Also
   1. Vector Borne Disease
   2. Prevention of Tick-borne Infection
   3. Tick Removal
2. Epidemiology
   1. Peak onset in summer and fall
   2. Endemic areas in United States (>50% of cases)
      1. Arkansas
      2. Missouri
      3. Oklahoma
3. Pathophysiology
   1. Francisella tularensis is causative organism
      1. Small gram-negative non-motile coccobacillus
   2. Carriers of F. tularensis
      1. Rabbits
      2. Wild rodents
      3. Tick Vector
         1. Amblyomma americanum (Lone star tick)
         2. Dermacentor variabilis (Dog tick)
   3. Transmission
      1. Tick bite (accounts for 50% of U.S. cases)
      2. Risk of exposure as Biological Weapon
   4. Incubation: 1 to 14 days
4. Symptoms: Constitutional (follows 3-5 day incubation)
   1. Fever and chills
   2. Headache
   3. Malaise or Fatigue
   4. Anorexia
   5. Vomiting
   6. Pharyngitis
   7. Abdominal Pain
   8. Diarrhea
   9. Chest discomfort
   10. Myalgias
5. Type Specific Signs (divided over 6 classic types)
   1. Glandular Type
      1. Localized, tender Lymphadenopathy
         1. Children: Cervical and occipital lymph nodes
         2. Adults: Inguinal lymph nodes
   2. Ulceroglandular Type (most common)
      1. Lymphadenopathy as in Glandular type
      2. Painful skin ulcer in region of Lymphadenopathy
   3. Oculoglandular Type
      1. Conjunctiva involvement
         1. Unilateral in 90% of cases
         2. Early symptoms
            1. Photophobia
            2. Increased Lacrimation
         3. Later signs
            1. Lid edema
            2. Painful Conjunctivitis
            3. Scleral injection
            4. Chemosis
            5. Small yellow Conjunctival ulcers or Papules
      2. Lymphadenopathy as in Glandular type above
         1. Preauricular, Submandibular, and Cervical nodes
   4. Pharyngeal Type
      1. Exudative Pharyngitis with severe Sore Throat
      2. Lymphadenopathy as in Glandular Type
         1. Cervical, pre-parotid and retropharyngeal nodes
   5. Typhoidal Type
      1. No significant Lymphadenopathy
      2. Profuse watery Diarrhea
   6. Pneumonic Type
      1. Non-productive cough
      2. Substernal and Pleuritic Chest Pain
      3. Infiltrates may be seen on Chest XRay
6. Labs
   1. Inflammatory markers normal
      1. Erythrocyte Sedimentation Rate (ESR) near normal
      2. Complete Blood Count
         1. White Blood Cell count near normal
   2. Sputum or blood testing
      1. Sputum or Blood Direct fluorescent Antibody
      2. Sputum Culture or Blood Culture
   3. Tularemia Serology
      1. Confirms diagnosis at two weeks
7. Management
   1. Treat for 10-14 days
   2. Streptomycin (not for Meningitis)
      1. Adult
         1. Initial: 7.5-10 mg/kg up to 500 mg IM q12 hours
         2. Once affebrile: 0.5 grams daily for 5 days
      2. Child: 15 mg/kg (up to 2 g) IM q12 hours
   3. Gentamicin for 7-14 days
      1. Adult: 3-5 mg/kg IM or IV qd
      2. Child: 2.5 mg/kg IM or IV q8 hours
   4. Ciprofloxacin (cartilage risk under age 18 years)
      1. Adult
         1. Initial: 400 mg IV q12 hours
         2. When Improved: 750 mg PO bid
      2. Child: 15 mg/kg (up to 500 mg) IV q12 hours
8. Prevention
   1. Live attenuated vaccine 0.1 ml dose via scarification
      1. Awaiting FDA approval
   2. Post-exposure prophylaxis (adult dosing below)
      1. Continue for 14 days or length of exposure
      2. Doxycycline 100 mg PO bid
      3. Ciprofloxacin 500 mg PO bid
      4. Tetracycline 500 mg PO qid
9. Prevention
   1. Live vaccine if high risk of exposure
10. Prognosis
    1. Mortality <2%
11. References
    1. Dennis (2001) JAMA 285(21):2763-73