Psittacosis

Psittacosis (ornithosis/chlamydiosis) is a contagious bird disease caused by Chlamydia psittaci. Turkeys/chickens/pigeons/ducks/geese/wildfowl all get it and transmit. Human infection from psittacine birds = psittacosis; from non-psittacine birds = ornithosis/asexual chlamydiosis. Often latent; symptoms: conjunctivitis/rhinitis/diarrhea.

Common Symptoms

Macule; chills; cyanosis; nausea; epistaxis

Causes and Pathogenesis

(1) Etiology: Chlamydiaceae, Chlamydia: C. psittaci/pneumoniae/trachomatis/pecorum (last not human-pathogenic). Obligate intracellular, filterable, eukaryote-energy parasites with cell wall/membrane/own enzymes; binary fission; unique developmental cycle; intracytoplasmic basophilic inclusions; Gram-negative. MOMP homology: C. psittaci vs pneumoniae 71%, vs trachomatis 68%; chromosomal DNA homology <10%. C. psittaci strains 20-100% DNA homology. New view: heterogeneous group causing enteritis/placentitis/mastitis/polyarthritis/meningoencephalitis/pneumonia/conjunctivitis/keratoconjunctivitis in many hosts. Discovered 1930 by Levinthal/Coles/Lillie (LCL bodies). Two forms: reticulate body (replicative) and elementary body (infectious, 0.3-0.4 µm). EB enters cell → RB → binary fission → new EB → cell lysis → reinfect. Cycle 24-48 h. Culture: BSC-1/BGMK/Hela/KB/McCoy/L cells, mouse macrophages, hamster kidney, yolk sac, CAM. Antigens: genus-specific LPS (heat-stable) and species-specific; preserved at -75°C/lyophilized in 7.5% glucose skim milk; ether-sensitive (30 min); 0.1% formalin/0.5% phenol/25% ethanol/40% methanol kills; 60°C/10 min. (2) Pathogenesis: enters via URT, multiplies in local monocytes, spreads hematogenously. Mainly lobular/interstitial pneumonia (lower lobes), alveolar exudate/fibrin/hemorrhage, thickened septa, edema/necrosis; liver focal necrosis, splenomegaly; also pleura/heart/kidney/CNS/GI. Basophilic inclusions in lung macrophages/pericardium/myocardium/stellate liver cells.

Treatment

TCM, supportive therapy

Preventive Measures

(1) Quarantine + tetracycline for imported parrots. (2) Avoid contact with infected pigeons/birds/dander/cages; chlortetracycline-feed 45 days for imported birds; isolate patients (droplet transmission). (3) Non-psittacine bird control is harder—comprehensive measures needed.

Department to Visit

It is recommended to visit the Infectious Diseases department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.