title: Prevalence of Chlamydia psittaci in the feral pigeon population of Basel, Switzerland.
abstract: Feral pigeons (Columba livia) are commonly infected with Chlamydia psittaci, the agent of psittacosis in humans. To assess the risk of zoonosis posed by feral pigeons in the urban environment, we determined the prevalence of Chlamydia psittaci by detection of the outer-membrane protein A (ompA) gene of this pathogen in pharyngeal and cloacal samples of 202 feral pigeons present in a loft in Basel, Switzerland. Additionally, we examined 620 fresh faecal droppings of feral pigeons at six public sites in Basel. The ompA gene of C. psittaci could be detected in only 17 (8.4 %) of the 202 feral pigeons in the loft. C. psittaci DNA was present in nine (2.0 %) of 447 of the pharyngeal swabs and 11 (3.2 %) of the 348 cloacal swabs. Genotyping of the ompA gene revealed genotype B in seven of the birds. In one bird, a mixed infection was detected with the genotypes A, B and E/B, which, to our knowledge is the first time such an infection has been reported. Some of these birds immigrated into the loft as adults. To our knowledge, this is the first study to document how the interconnectedness between feral pigeon subpopulations favours the spread of C. psittaci. C. psittaci DNA was not detected in any of the faecal droppings collected at the six public areas. In spite of the low levels of C. psittaci shedding by feral pigeons in Basel, close contact to feral pigeons bears the risk of zoonotic transmission of C. psittaci. Feral pigeon management programmes and public education should be implemented to reduce the risk of a pigeon-to-human transmission of such pathogenic agents.
authors.affiliation: Department of Biomedicine, Institute of Anatomy, University of Basel, Pestalozzistrasse 20, CH-4056 Basel, Switzerland.
authors.forename: Ila
authors.initials: I
authors.lastname: Geigenfeind
authors.affiliation: Department of Molecular Biotechnology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
authors.forename: Daisy
authors.initials: D
authors.lastname: Vanrompay
authors.affiliation: Department of Biomedicine, Institute of Anatomy, University of Basel, Pestalozzistrasse 20, CH-4056 Basel, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Haag-Wackernagel
mesh_terms: D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001715:Bird Diseases / Q000453:epidemiology* / Q000382:microbiology*; D002691:Chlamydophila psittaci / Q000302:isolation & purification*; D002988:Cloaca / Q000382:microbiology; D060085:Coinfection / Q000382:microbiology; D010856:Columbidae / Q000382:microbiology*; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D010614:Pharynx / Q000382:microbiology; D015995:Prevalence; D009956:Psittacosis / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D013557:Switzerland / Q000453:epidemiology
chemical_list: D001425:Bacterial Outer Membrane Proteins; C078167:OMPA outer membrane proteins