title: Temporal dynamics, diversity, and interplay in three components of the virodiversity of a Mallard population: influenza A virus, avian paramyxovirus and avian coronavirus.
abstract: Multiple infections, or simultaneous infection of a host with multiple parasites, are the rule rather than the exception. Interactions between co-occurring pathogens in a population may be mutualistic, competitive or facilitative. For some pathogen combinations, these interrelated effects will have epidemiological consequences; however this is as yet poorly incorporated into practical disease ecology. For example, screening of Mallards for influenza A viruses (IAV) have repeatedly revealed high prevalence and large subtype diversity in the Northern Hemisphere. Other studies have identified avian paramyxovirus type 1 (APMV-1) and coronaviruses (CoVs) in Mallards, but without making inferences on the larger viral assemblage. In this study we followed 144 wild Mallards across an autumn season in a natural stopover site and constructed infection histories of IAV, APMV-1 and CoV. There was a high prevalence of IAV, comprising of 27 subtype combinations, while APMV-1 had a comparatively low prevalence (with a peak of 2%) and limited strain variation, similar to previous findings. Avian CoVs were common, with prevalence up to 12%, and sequence analysis identified different putative genetic lineages. An investigation of the dynamics of co-infections revealed a synergistic effect between CoV and IAV, whereby CoV prevalence was higher given that the birds were co-infected with IAV. There were no interactive effects between IAV and APMV-1. Disease dynamics are the result of an interplay between parasites, host immune responses, and resources; and is imperative that we begin to include all factors to better understand infectious disease risk.
authors.affiliation: Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, SE-391 82 Kalmar, Sweden.
authors.forename: Michelle
authors.initials: M
authors.lastname: Wille
authors.affiliation: Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, SE-391 82 Kalmar, Sweden; CIRAD, Campus international de Baillarguet, 34398 Montpellier, France.
authors.forename: Alexis
authors.initials: A
authors.lastname: Avril
authors.affiliation: Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, SE-391 82 Kalmar, Sweden.
authors.forename: Conny
authors.initials: C
authors.lastname: Tolf
authors.affiliation: Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, SE-391 82 Kalmar, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Schager
authors.affiliation: Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, SE-391 82 Kalmar, Sweden.
authors.forename: Sara
authors.initials: S
authors.lastname: Larsson
authors.affiliation: Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, SE-391 82 Kalmar, Sweden.
authors.forename: Olivia
authors.initials: O
authors.lastname: Borg
authors.affiliation: Section of Infectious Diseases, Department of Medical Sciences, Uppsala University, SE-751 85 Uppsala, Sweden; Zoonosis Science Centre, Department of Medical Biochemistry and Microbiology, Uppsala University, SE-751 85 Uppsala, Sweden.
authors.forename: Björn
authors.initials: B
authors.lastname: Olsen
authors.affiliation: Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, SE-391 82 Kalmar, Sweden. Electronic address: jonas.waldenstrom@lnu.se.
authors.forename: Jonas
authors.initials: J
authors.lastname: Waldenström
mesh_terms: D000818:Animals; D018109:Avulavirus / Q000145:classification / Q000235:genetics*; D001715:Bird Diseases / Q000276:immunology / Q000821:virology*; D060085:Coinfection / Q000276:immunology / Q000821:virology; D017934:Coronavirus / Q000145:classification / Q000235:genetics*; D004372:Ducks; D005260:Female; D014644:Genetic Variation; D009980:Influenza A virus / Q000145:classification / Q000235:genetics*; D008297:Male; D010802:Phylogeny; D015995:Prevalence; D012367:RNA, Viral / Q000032:analysis; D017423:Sequence Analysis, RNA
chemical_list: D012367:RNA, Viral
keywords: Avian paramyxovirus; Co-infection; Coronavirus; Disease dynamics; Influenza A virus; Newcastle disease virus