title: Evidence for co-evolution of West Nile Virus and house sparrows in North America.
abstract: West Nile virus (WNV) has been maintained in North America in enzootic cycles between mosquitoes and birds since it was first described in North America in 1999. House sparrows (HOSPs; Passer domesticus) are a highly competent host for WNV that have contributed to the rapid spread of WNV across the U.S.; however, their competence has been evaluated primarily using an early WNV strain (NY99) that is no longer circulating. Herein, we report that the competence of wild HOSPs for the NY99 strain has decreased significantly over time, suggesting that HOSPs may have developed resistance to this early WNV strain. Moreover, recently isolated WNV strains generate higher peak viremias and mortality in contemporary HOSPs compared to NY99. These data indicate that opposing selective pressures in both the virus and avian host have resulted in a net increase in the level of host competence of North American HOSPs for currently circulating WNV strains.
authors.affiliation: Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, United States of America.
authors.forename: Nisha K
authors.initials: NK
authors.lastname: Duggal
authors.affiliation: Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, United States of America; Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America.
authors.forename: Angela
authors.initials: A
authors.lastname: Bosco-Lauth
authors.affiliation: Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Bowen
authors.affiliation: Center for Vectorborne Diseases, University of California, Davis, Davis, California, United States of America.
authors.forename: Sarah S
authors.initials: SS
authors.lastname: Wheeler
authors.affiliation: Center for Vectorborne Diseases, University of California, Davis, Davis, California, United States of America.
authors.forename: William K
authors.initials: WK
authors.lastname: Reisen
authors.affiliation: United States Department of Agriculture, Lakewood, Colorado, United States of America.
authors.forename: Todd A
authors.initials: TA
authors.lastname: Felix
authors.affiliation: Departments of Pathology and Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America.
authors.forename: Brian R
authors.initials: BR
authors.lastname: Mann
authors.affiliation: Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, United States of America; Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America.
authors.forename: Hannah
authors.initials: H
authors.lastname: Romo
authors.affiliation: Departments of Pathology and Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America.
authors.forename: Daniele M
authors.initials: DM
authors.lastname: Swetnam
authors.affiliation: Departments of Pathology and Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America.
authors.forename: Alan D T
authors.initials: AD
authors.lastname: Barrett
authors.affiliation: Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, United States of America.
authors.forename: Aaron C
authors.initials: AC
authors.lastname: Brault
mesh_terms: D000818:Animals; D005075:Biological Evolution; D005838:Genotype; D009656:North America; D046370:Sparrows / Q000821:virology*; D014766:Viremia / Q000635:transmission; D014779:Virus Replication; D014902:West Nile virus / Q000145:classification* / Q000235:genetics