Direct complement fixation and isolation attempts for detecting Chlamydia psittaci infection of psittacine birds

Serum and fecal specimens from 147 birds were tested for Chlamydia psittaci. Isolation rates ranged from 3.4% of 88 birds that had titers less than 8, to 50% of six birds that had titers greater than or equal to 128. Testing of 44 paired sera revealed a significant titer increase in 5 pairs, a significant titer decrease in 8 pairs, and a stable titer in 31 pairs. The examination of both feces and serum is recommended for determining Chlamydia psittaci infections in individual live psittacine birds.