EPIDEMIOLOGICAL SURVEY OF CHIAMYDIAL INFECTION IN FERAL PIGEONS AND CROWS IN HOKKAIDO, AND STUDIES ON THE PREPARATION OF A COMPLEMENT-FIXATION ANTIGEN FOR PSITTACOSIS

An epidemiological situation of psittacosis in feral pigeons and crows was elucidated by isolating Chlamydia psittaci (C. psiltaci)from these birds in Hokkaido and by examining the presence of chlamydial antibodies in them. A new method was developed to prepare a complement-fixation (CF) antigen from chyamydial organisms grown in tissue culture. Antigenicity and immunogenicity of the CF antigen were also analyzed. The results were summarized as follows: 1) C. psittaci was isolated from 9 of 119 pigeons, and no chlamydial organisms were isolated from 179 crows. Of the 105 pigeons tested, 32 (30.5%) had chlamydia-positive CF titers of 1 : 8 or greater. Of the 82 crows tested, 18 (22%) were positive in the indirect CF test. Furthermore, high rates of hemagglutination inhibition antibodies were found in both groups of birds. 2) Cycloheximide tretment of L-929 cells enhanced the yield of infectious C.