Psittacosis natural history

If left untreated, psittacosis usually presents as flu-like symptoms or an atypical pneumonia. In the first week of psittacosis, the symptoms mimic typhoid fever, including prostrating high fevers, arthralgias, diarrhea, conjunctivitis, epistaxis, and leukopenia. Headache can be so severe that it suggests meningitis and some nuchal rigidity. Towards the end of the first week, stupor or even coma can result in severe cases. The second week is more akin to acute bacteremic pneumococcal pneumonia with continuous high fevers, cough, and dyspnea. Some complications include respiratory failure, acute tubular necrosis, hemolytic anemia, endocarditis, hepatitis, encephalitis and, in some cases, death.

Psittacosis presents chiefly as an atypical pneumonia. In the first week of psittacosis, the symptoms mimic typhoid fever, including prostrating high fevers, arthralgias, diarrhea, conjunctivitis, epistaxis, and leukopenia. Severe headache and the presence of nuchal rigidity may suggest meningitis. Towards the end of the first week, stupor and coma result in severe cases. The second week is more akin to acute bacteremic pneumococcal pneumonia with continuous high fevers, cough, and dyspnea. If untreated, psittacosis progresses as following:

• Stage of flu-like syndrome
• Moderate pneumonia with X-ray findings
• Severe pneumonia
• Respiratory failure and sepsis

Complications that can develop as a result of psittacosis include:^{[1][2][3][4][4][5][6][7]}

• Respiratory failure
• Acute tubular necrosis
• Hemolytic anemia
• Endocarditis
• Hepatitis
• Endocarditis
• Reactive arthritis
• Chronic follicular conjunctivitis
• Lymphoma
• Gestational psittacosis
• Encephalitis, which is rare but fatal.

Psittacosis is a treatable infectious disease. With appropriate antibiotic therapy, the prognosis is good. If the disease is complicated by renal failure or respiratory failure, the prognosis is poor.