title: Dual-pathogen etiology of avian trichomonosis in a declining band-tailed pigeon population.
abstract: The Pacific Coast band-tailed pigeon (Patagioenas fasciata monilis) is a migratory game bird of North America that is at risk for population decline. Epidemics of avian trichomonosis caused by upper digestive tract infection with Trichomonas spp. protozoa in these and other doves and pigeons of the United States are sporadic, but can involve tens of thousands of birds in a single event. Herein, we analyze the role of trichomonosis in band-tailed pigeon mortality and relate spatial, temporal and demographic patterns of parasite transmission to the genetic background of the infecting organism. Infections were most common in adult birds and prevalence was high in band-tailed pigeons sampled at mortality events (96%) and rehabilitation centers (36%) compared to those that were hunter-killed (11%) or live-caught (4%). During non-epidemic periods, animals were primarily infected with T. gallinae Fe-hydrogenase subtype A2, and were less often infected with either T. gallinae subtype A1 (the British finch epidemic strain), T. stableri n. sp. (a T. vaginalis-like species), or Tritrichomonas blagburni n. sp.-like organisms. Birds sampled during multiple epidemics in California were only infected with T. gallinae subtype A2 and T. stableri. The non-clonal etiology of avian trichomonosis outbreaks in band-tailed pigeons and the risk of spill-over to raptor and passerine species highlights the need for additional studies that clarify the host range and evolutionary relationships between strains of Trichomonas spp. in regions of trichomonosis endemicity.
authors.affiliation: Wildlife Health Center, School of Veterinary Medicine, University of California, Davis, CA, United States. Electronic address: wildlifehealth@ucdavis.edu.
authors.forename: Yvette A
authors.initials: YA
authors.lastname: Girard
authors.affiliation: Wildlife Investigations Laboratory, California Department of Fish and Wildlife, Rancho Cordova, CA, United States.
authors.forename: Krysta H
authors.initials: KH
authors.lastname: Rogers
authors.affiliation: California Animal Health and Food Safety Laboratory, University of California, Davis, CA, United States.
authors.forename: Leslie W
authors.initials: LW
authors.lastname: Woods
authors.affiliation: California Animal Health and Food Safety Laboratory, University of California, Davis, CA, United States.
authors.forename: Nadira
authors.initials: N
authors.lastname: Chouicha
authors.affiliation: Wildlife Health Center, School of Veterinary Medicine, University of California, Davis, CA, United States.
authors.forename: Woutrina A
authors.initials: WA
authors.lastname: Miller
authors.affiliation: Wildlife Health Center, School of Veterinary Medicine, University of California, Davis, CA, United States.
authors.forename: Christine K
authors.initials: CK
authors.lastname: Johnson
mesh_terms: D000818:Animals; D001715:Bird Diseases / Q000469:parasitology; D002140:California / Q000453:epidemiology; D010856:Columbidae / Q000469:parasitology*; D016054:DNA, Protozoan / Q000235:genetics; D046369:Finches / Q000469:parasitology*; D058507:Host Specificity; D008969:Molecular Sequence Data; D014244:Trichomonas / Q000145:classification / Q000235:genetics*; D014245:Trichomonas Infections / Q000453:epidemiology* / Q000401:mortality / Q000635:transmission / Q000662:veterinary*
chemical_list: D016054:DNA, Protozoan
keywords: Avian trichomonosis; Band-tailed pigeon; Fe-hydrogenase; ITS1/5.8S rRNA/ITS2; Trichomonas gallinae; Trichomonas stableri