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