Prevalence and genotype distribution of Chlamydia psittaci in feral Canada geese (Branta canadensis) in Belgium

Chlamydia (C.) psittaci is a zoonotic pathogen with a wide range of avian hosts and worldwide geographical spread. Zoonotic transfer occurs by inhalation or direct contact and may cause psittacosis or parrot disease. Host reservoirs of particular epidemiological interest include gregarious or migratory species, as colonial behaviour facilitates microbial spread amongst conspecifics and a migratory ecology permits disperse over a wide geographic region. The current study detected C. psittaci antibodies in 76 of 81 (93.8%) feral Canada geese (Branta canadensis) using a species-specific ELISA. Viable C. psittaci were isolated from pharyngeal swabs of 47 of 81 (58%) birds and subsequent ompA-based genotyping revealed genotypes E, B and E/B. Absence of clinical symptoms in these geese could reflect a strong natural protection or a persistent infection. Canada geese are considered an important alien species in Europe. Current results denote that this avian reservoir poses a considerable risk to native wildlife as a potential source of C. psittaci