CLINICAL DESCRIPTION

An illness occurring sporadically in persons exposed to infected birds or their feathers or excreta. It is most commonly characterized by fever, chills, headache, photophobia, lower or upper respiratory disease, and myalgia. The incubation period is 1 to 4 weeks.

1. CONFIRMED

   A clinically compatible case AND:

   • Isolation of Chlamydia psittaci from respiratory secretions, OR

   • Fourfold or greater increase in antibody against Chlamydia psittaci by complement fixation or microimmunofluorescence (MIF) to a reciprocal titer of greater than or equal to 32 between paired acute- and convalescent-phase serum specimens, OR

   • Presence of immunoglobulin M (IgM) antibody against Chlamydia psittaci by MIF to a reciprocal titer of greater than or equal to 16.
     
     

   NOTE: The serologic findings by CF also may occur as a result of infection with Chlamydia pneumoniae or Chlamydia trachomatis. The MIF might be more specific for infection with Chlamydia psittaci, but experience with and availability of this newer test are more limited.
   
   

2. PROBABLE

   A clinically compatible case:

   • That is epidemiologically linked to a confirmed case, OR

   • That has supportive serology (e.g., Chlamydia psittaci titer of greater than or equal to 32 in one or more specimens obtained after onset of symptoms).
     
     
3. POSSIBLE
   
   Not used
   
   

What should you know about Psittacosis?