[Importance and distribution of serological findings of ornithosis-psittacosis in semi-domestic pigeons].

Ornithosis-psittacosis is a widely distributed disease in birds throughout the world. A serological study by the complement-fixation test and a few isolation of Chlamyqia were performed on feral pigeon population of Antwerpen city. The incidence of positive cases in Antwerpen averages 58.51 %. For each serum, a serological index (S. I.) was calculated with regard to the intensity of immunological response in different dilutions: S. I. seems to suggest an endemic status of the disease in Antwerpen. Evolution in time of the prevalence and the serological response shows the presence of two peaks: the first one in spring and the last one in summer. This might be explained by some factors influencing the transmission of the infection: between them, one must emphasize the pigeons habits and the ectoparasites.