Ornithosis/psittacosis as a notifiable disease in Switzerland is caused by Chlamydophila psittaci occuring world-wide in 375 different bird species. The different strains of Chlamydophila psittaci in birds are named as genotypes A through F and have markedly different virulence traits and zoonotic potentials. Between 1941 and 2003, 78 cases of psittacosis in humans transmitted from feral pigeons are reported in the literature. In Switzerland, about 5 to 10 cases of ornithosis in birds are reported annually, whereas mainly captive birds are examined and found to be diseased. To date, little is known about the prevalence of the agent in the wild bird population. This lack of knowledge leads us to examine the occurence of Chlamydophila psittaci in the Swiss wild bird population. Already available samples from the surveillance for avian influenza in wild birds and from the archive of the National Reference Center for Poultry and Rabbit Diseases, University of Zurich will be examined by the sensitive and specific microarray method for Chlamydophila psittaci to get insight into the epidemiological situation of ornithosis in wild birds in Switzerland. Genotyping of the positive cases will be performed using a second microarray chip. The results of the study will elucidate the potential risk for domestic poultry and public health due to ornithosis in wild birds in Switzerland and will show the potential need of preventive measurements.
