Psittacosis natural history

Overview
It presents chiefly as an atypical pneumonia. In the first week of psittacosis the symtoms mimic typhoid fever: prostrating high fevers, arthralgias, diarrhea, conjunctivitis, epistaxis and leukopenia. Headache can be so severe that suggests meningitis and some nuchal rigidity is not unusual. Towards the end of first week stupor or even comacan result in severe cases.

The second week is more akin of acute bacteraemic pneumococcal pneumonia with continuous high fevers, cough and dyspnoea.

Complications
Complications in the form of endocarditis, hepatitis, myocarditis, arthritis, keratoconjunctivitis, and neurologic complications (encephalitis) may occasionally occur. Severe pneumonia requiring intensive-care support may also occur. Fatal cases have been reported (less than 1% of cases).