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Etiology and Epidemiology !!navigator!!

Most avian species can harbor C. psittaci, but psittacine birds (e.g., parrots, parakeets) are most often infected. Human infections are uncommon and occur only as a zoonosis.

Clinical Manifestations !!navigator!!

Psittacosis in humans can range in severity from asymptomatic or mild infections to acute primary atypical pneumonia (which can be fatal in 10% of untreated cases) to severe chronic pneumonia.

  • After an incubation period of >5-19 days, pts present with fever, chills, muscular aches and pains, severe headaches, hepatomegaly and/or splenomegaly, and GI symptoms.
  • Cardiac complications may include endocarditis and myocarditis.

Diagnosis !!navigator!!

This diagnosis is confirmed by serologic studies.

  • The gold standard is the MIF test.
  • Any antibody titer >1:16 or a fourfold rise between paired acute- and convalescent-phase serum samples, in combination with a clinically compatible syndrome, can be used to diagnose psittacosis.

Treatment: C. Psittaci Infections

  • Tetracycline (250 mg PO qid for 3 weeks) is the antibiotic of choice.
  • Erythromycin (500 mg PO qid) is an alternative agent.

For a more detailed discussion, see Gaydos CA, Quinn TC: Chlamydial Infections, Chap. 213, p. 1165, in HPIM-19.


Outline

Outline

Section 7. Infectious Diseases