title: Ecological factors driving the long-term evolution of influenza's host range.
abstract: The evolution of a pathogen's host range is shaped by the ecology of its hosts and by the physiological traits that determine host specificity. For many pathogen traits, there is a trade-off: a phenotype suitable for infecting one set of hosts poorly infects another. Introducing and analysing a simple evo-epidemiological model, here we study how such a trade-off is expected to affect evolution of the host ranges of influenza viruses. We examine a quantitative trait underlying host specificity, given by an influenza virus's degree of adaptation to certain conformations of sialic acid receptors, and investigate how this receptor preference evolves in a minimal network of host species, including humans, that differ in life history and receptor physiology. Using adaptive dynamics theory, we establish thresholds in interspecific transmission rates and host population sizes that govern the emergence and persistence of human-adapted viruses. These ecological thresholds turn out to be largely independent of the strength of the evolutionary trade-off, underscoring the importance of ecological conditions in determining a disease's host range.
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Michigan, , 830 North University Avenue, Ann Arbor, MI 48109, USA. scobey@hsph.harvard.edu
authors.forename: Sarah
authors.initials: S
authors.lastname: Cobey
authors.forename: Mercedes
authors.initials: M
authors.lastname: Pascual
authors.forename: Ulf
authors.initials: U
authors.lastname: Dieckmann
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D005075:Biological Evolution; D001717:Birds / Q000821:virology; D002415:Cats / Q000821:virology; D058507:Host Specificity; D054884:Host-Pathogen Interactions; D006801:Humans; D007251:Influenza, Human / Q000635:transmission* / Q000821:virology; D009975:Orthomyxoviridae / Q000378:metabolism / Q000472:pathogenicity*; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011991:Receptors, Virus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D011956:Receptors, Cell Surface; D011991:Receptors, Virus; C092488:sialic acid receptor
references.citation: Nature. 2003 Oct 2;425(6957):480-4
references.pmid: 14523438
references.citation: Rev Sci Tech. 2004 Aug;23(2):453-65
references.pmid: 15702713
references.citation: J Gen Virol. 1994 Sep;75 ( Pt 9):2183-8
references.pmid: 8077918
references.citation: Virology. 2001 Mar 15;281(2):156-62
references.pmid: 11277689
references.citation: Emerg Infect Dis. 2005 Dec;11(12):1842-7
references.pmid: 16485468
references.citation: Avian Dis. 2003;47(3 Suppl):996-1001
references.pmid: 14575100
references.citation: Evolution. 2004 Mar;58(3):455-69
references.pmid: 15119430
references.citation: Proc Natl Acad Sci U S A. 2009 Oct 6;106(40):17175-80
references.pmid: 19805083
references.citation: Science. 2001 May 11;292(5519):1102-5
references.pmid: 11352064
references.citation: Bioessays. 2003 Jul;25(7):657-71
references.pmid: 12815721
references.citation: J Vet Med Sci. 1999 Aug;61(8):955-8
references.pmid: 10487239
references.citation: Proc Biol Sci. 2005 Sep 22;272(1575):1949-56
references.pmid: 16191602
references.citation: Am Nat. 2004 Apr;163(4):518-31
references.pmid: 15122500
references.citation: Nature. 2003 Dec 11;426(6967):658-61
references.pmid: 14668863
references.citation: Virology. 2005 Apr 10;334(2):276-83
references.pmid: 15780877
references.citation: Trends Ecol Evol. 1992 Jun;7(6):198-202
references.pmid: 21236007
references.citation: Proc Biol Sci. 2005 May 7;272(1566):971-7
references.pmid: 16024354
references.citation: Virology. 2003 Jan 20;305(2):267-75
references.pmid: 12573572
references.citation: J Virol. 2000 Sep;74(18):8502-12
references.pmid: 10954551
references.citation: Mol Biol (Mosk). 2002 May-Jun;36(3):542-9
references.pmid: 12068641
references.citation: Microbiol Rev. 1992 Mar;56(1):152-79
references.pmid: 1579108
references.citation: Nat Med. 2004 Dec;10(12 Suppl):S77-81
references.pmid: 15577935
references.citation: J Math Biol. 1996;34(5-6):579-612
references.pmid: 8691086
references.citation: Lancet. 2004 Jan 17;363(9404):234-6
references.pmid: 14738798