title: Distribution, diversity and drivers of blood-borne parasite co-infections in Alaskan bird populations.
abstract: Avian species are commonly infected by multiple parasites, however few studies have investigated the environmental determinants of the prevalence of co-infection over a large scale. Here we believe that we report the first, detailed ecological study of the prevalence, diversity and co-infections of four avian blood-borne parasite genera: Plasmodium spp., Haemoproteus spp., Leucocytozoon spp. and Trypanosoma spp. We collected blood samples from 47 resident and migratory bird species across a latitudinal gradient in Alaska. From the patterns observed at collection sites, random forest models were used to provide evidence of associations between bioclimatic conditions and the prevalence of parasite co-infection distribution. Molecular screening revealed a higher prevalence of haematozoa (53%) in Alaska than previously reported. Leucocytozoons had the highest diversity, prevalence and prevalence of co-infection. Leucocytozoon prevalence (35%) positively correlated with Trypanosoma prevalence (11%), negatively correlated with Haemoproteus prevalence (14%) and had no correlation with Plasmodium prevalence (7%). We found temperature, precipitation and tree cover to be the primary environmental drivers that show a relationship with the prevalence of co-infection. The results provide insight into the impacts of bioclimatic drivers on parasite ecology and intra-host interactions, and have implications for the study of infectious diseases in rapidly changing environments.
authors.affiliation: Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132, USA. Electronic address: ksouvong@gmail.com.
authors.forename: Khouanchy S
authors.initials: KS
authors.lastname: Oakgrove
authors.affiliation: Center for Tropical Research, Institute of the Environment and Sustainability, University of California, Los Angeles, CA 90095, USA.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Harrigan
authors.affiliation: Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132, USA.
authors.forename: Claire
authors.initials: C
authors.lastname: Loiseau
authors.affiliation: Alaska Songbird Institute, PO Box 82035, Fairbanks, AK 99708, USA.
authors.forename: Sue
authors.initials: S
authors.lastname: Guers
authors.affiliation: Bureau of Land Management, Anchorage Field Office, 4700 BLM Road, Anchorage, AK 99507, USA.
authors.forename: Bruce
authors.initials: B
authors.lastname: Seppi
authors.affiliation: Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132, USA.
authors.forename: Ravinder N M
authors.initials: RN
authors.lastname: Sehgal
mesh_terms: D000413:Alaska / Q000453:epidemiology; D000818:Animals; D044822:Biodiversity; D001715:Bird Diseases / Q000097:blood / Q000453:epidemiology / Q000469:parasitology*; D001717:Birds; D017848:Blood-Borne Pathogens / Q000302:isolation & purification*; D060085:Coinfection; D008954:Models, Biological; D010271:Parasites / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D010273:Parasitic Diseases, Animal / Q000097:blood / Q000453:epidemiology / Q000469:parasitology*; D010802:Phylogeny
keywords: Alaska; Arctic; Co-infections; Haemoproteus; Leucocytozoon; Plasmodium; Random forest models; Trypanosoma