title: Strain-related variation in the persistence of influenza A virus in three types of water: distilled water, filtered surface water, and intact surface water.
abstract: BACKGROUND
  The persistence of influenza A (IA) virus in aquatic habitats has been demonstrated to be a determinant for virus transmission dynamics in wild duck populations. In this study, we investigated virus strain-related variation in persistence in water for nine wild duck isolated IA viruses of three subtypes (H3N8, H4N6, and H8N4).
  
  
  RESULTS
  We experimentally estimated the loss of infectivity over time in three different types of water: distilled, filtered surface water, and intact surface water. All viruses persisted longest in distilled water followed by filtered surface water with markedly reduced durations of persistence observed in the intact surface water. Strain-related variations were observed in distilled and filtered surface water but limited variation was observed in the intact surface water.
  
  
  CONCLUSIONS
  Our findings suggest that the role of surface water for long-term (between years) maintenance of AI viruses in the environment may be limited, and suggest that the physico-chemical characteristics of water, as well as microorganisms, may be of strong importance. Results also indicate that the extent of strain-related variation observed in distilled water may overestimate persistence abilities for IA viruses in the wild and supports the need to develop experiments that account for these effects to assess subtype, genotype, as well as spatial and temporal variation in the persistence of IA viruses in aquatic habitats.
authors.affiliation: Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602, USA. skeeler@uga.edu
authors.forename: Shamus P
authors.initials: SP
authors.lastname: Keeler
authors.forename: Camille
authors.initials: C
authors.lastname: Lebarbenchon
authors.forename: David E
authors.initials: DE
authors.lastname: Stallknecht
mesh_terms: D000818:Animals; D002642:Chick Embryo; D004372:Ducks / Q000821:virology; D017753:Ecosystem; D006863:Hydrogen-Ion Concentration; D053123:Influenza A Virus, H3N8 Subtype / Q000145:classification / Q000302:isolation & purification / Q000472:pathogenicity*; D061985:Madin Darby Canine Kidney Cells; D009976:Orthomyxoviridae Infections / Q000821:virology; D013045:Species Specificity; D013997:Time Factors; D014776:Virus Cultivation; D014867:Water / Q000032:analysis* / Q000737:chemistry; D014871:Water Microbiology
chemical_list: D014867:Water