Psittacosis

Aka: Psittacosis, Chlamydophila psittaci, Chlamydia psittaci, Parrot Fever

1. Etiology
   1. Chlamydophila psittaci (Chlamydia psittaci)
   2. Bacteria found in wild and domestic birds (5-8% of otherwise healthy birds carry this infection)
2. Risk Factors: Transmission
   1. Pet owners of birds (e.g. Parrots, cockatiels, parakeets, macaws)
   2. Poultry farmers (turkeys are among the highest risk)
   3. Poultry processing plants
   4. Visit to aviary
   5. Veterinarians
3. Pathophysiology: Transmission
   1. Inhalation of aerosolized infective particles
   2. Exposure to feces, urine, nasal secretions, feathers, and dust of infected birds
   3. Some pet owners kiss their birds, therefore transmitting the bacteria
   4. Livestock, cats and dogs may act as intermediaries for human infection
   5. Human to human transmission is rare
4. Presentations: Follows 5-15 day incubation period
   1. Subclinical, asymptomatic infection (common)
   2. Flu-like illness
   3. Mono-like illness (fever, Pharyngitis, hepatosplenomegaly)
   4. Typhoid-like illness (fever, Bradycardia, Splenomegaly)
   5. Atypical Pneumonia (fever, non-productive cough, Headache)
5. Symptoms: Atypical Pneumonia
   1. Fever (>50% of cases)
   2. Non-productive cough (>50% of cases)
   3. Headache (>30% of cases)
   4. Myalgias and chills
6. Signs: Atypical Pneumonia
   1. Fever
   2. Pharyngeal erythema
   3. Pulmonary rales
   4. Hepatomegaly
   5. Horder's Spots
      1. Similar to Typhoid Fever related Rose Spots
      2. Pink, blaching maculopapular rash
7. Complications: Complications are rare
   1. Acute Respiratory Distress Syndrome (ARDS)
   2. Pericarditis
   3. Endocarditis
   4. Hepatitis
   5. Reactive Arthritis
8. Labs
   1. Complete Blood Count
      1. Slight Leukocytosis with Left Shift
   2. Liver Function Tests
      1. Increased Alkaline Phosphatase
   3. Blood and Sputum Cultures are not recommended due to risk of transmission
9. Diagnosis
   1. C. Psittaci titers
10. Differential Diagnosis
    1. See Atypical Pneumonia
    2. See Typhoid Fever
11. Imaging: Chest XRay
    1. Lobar Pneumonia is most common
    2. Atypical patterns also occur
12. Management
    1. Tetracycline 500 mg orally four times daily for 10-21 days or
    2. Doxycycline 100 mg orally twice daily for 10-21 days
13. References
    1. Schlossberg in Mandell (2005) Infectious Disease, Chapter 178
    2. Schlossberg (1993) Arch Intern Med 153:2594-6
    3. Yung (1988) Med J Aust 148:228-33