title: Quantitative transmission characteristics of different H5 low pathogenic avian influenza viruses in Muscovy ducks.
abstract: EU annual serosurveillance programs show that domestic duck flocks have the highest seroprevalence of H5 antibodies, demonstrating the circulation of notifiable avian influenza virus (AIV) according to OIE, likely low pathogenic (LP). Therefore, transmission characteristics of LPAIV within these flocks can help to understand virus circulation and possible risk of propagation. This study aimed at estimating transmission parameters of four H5 LPAIV (three field strains from French poultry and decoy ducks, and one clonal reverse-genetics strain derived from one of the former), using a SIR model to analyze data from experimental infections in SPF Muscovy ducks. The design was set up to accommodate rearing on wood shavings with a low density of 1.6 ducks/m(2): 10 inoculated ducks were housed together with 15 contact-exposed ducks. Infection was monitored by RNA detection on oropharyngeal and cloacal swabs using real-time RT-PCR with a cutoff corresponding to 2-7 EID50. Depending on the strain, the basic reproduction number (R0) varied from 5.5 to 42.7, confirming LPAIV could easily be transmitted to susceptible Muscovy ducks. The lowest R0 estimate was obtained for a H5N3 field strain, due to lower values of transmission rate and duration of infectious period, whereas reverse-genetics derived H5N1 strain had the highest R0. Frequency and intensity of clinical signs were also variable between strains, but apparently not associated with longer infectious periods. Further comparisons of quantitative transmission parameters may help to identify relevant viral genetic markers for early detection of potentially more virulent strains during surveillance of LPAIV.
authors.affiliation: Anses (French Agency for Food, Environmental and Occupational Health & Safety), Ploufragan/Plouzané Laboratory, Avian and Rabbit Virology Immunology and Parasitology Unit, France; Université Européenne de Bretagne, France. Electronic address: eric.niqueux@anses.fr.
authors.forename: Éric
authors.initials: É
authors.lastname: Niqueux
authors.affiliation: Anses (French Agency for Food, Environmental and Occupational Health & Safety), Ploufragan/Plouzané Laboratory, Avian and Rabbit Virology Immunology and Parasitology Unit, France; Université Européenne de Bretagne, France.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Picault
authors.affiliation: Université Européenne de Bretagne, France; Anses (French Agency for Food, Environmental and Occupational Health & Safety), Ploufragan/Plouzané Laboratory, Avian Experimentation and Breeding Service, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Amelot
authors.affiliation: Anses (French Agency for Food, Environmental and Occupational Health & Safety), Ploufragan/Plouzané Laboratory, Avian and Rabbit Virology Immunology and Parasitology Unit, France; Université Européenne de Bretagne, France.
authors.forename: Chantal
authors.initials: C
authors.lastname: Allée
authors.affiliation: Anses (French Agency for Food, Environmental and Occupational Health & Safety), Ploufragan/Plouzané Laboratory, Avian and Rabbit Virology Immunology and Parasitology Unit, France; Université Européenne de Bretagne, France.
authors.forename: Josiane
authors.initials: J
authors.lastname: Lamandé
authors.affiliation: Anses (French Agency for Food, Environmental and Occupational Health & Safety), Ploufragan/Plouzané Laboratory, Avian and Rabbit Virology Immunology and Parasitology Unit, France; Université Européenne de Bretagne, France.
authors.forename: Carole
authors.initials: C
authors.lastname: Guillemoto
authors.affiliation: Anses (French Agency for Food, Environmental and Occupational Health & Safety), Ploufragan/Plouzané Laboratory, Avian and Rabbit Virology Immunology and Parasitology Unit, France; Université Européenne de Bretagne, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Pierre
authors.affiliation: Anses (French Agency for Food, Environmental and Occupational Health & Safety), Ploufragan/Plouzané Laboratory, Avian and Rabbit Virology Immunology and Parasitology Unit, France; Université Européenne de Bretagne, France.
authors.forename: Pascale
authors.initials: P
authors.lastname: Massin
authors.affiliation: Anses (French Agency for Food, Environmental and Occupational Health & Safety), Ploufragan/Plouzané Laboratory, Avian and Rabbit Virology Immunology and Parasitology Unit, France; Université Européenne de Bretagne, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Blot
authors.affiliation: Anses (French Agency for Food, Environmental and Occupational Health & Safety), Ploufragan/Plouzané Laboratory, Avian and Rabbit Virology Immunology and Parasitology Unit, France; Université Européenne de Bretagne, France.
authors.forename: François-Xavier
authors.initials: FX
authors.lastname: Briand
authors.affiliation: Université Européenne de Bretagne, France; Anses (French Agency for Food, Environmental and Occupational Health & Safety), Ploufragan/Plouzané Laboratory, Swine Epidemiology and Welfare Research Unit, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Rose
authors.affiliation: Anses (French Agency for Food, Environmental and Occupational Health & Safety), Ploufragan/Plouzané Laboratory, Avian and Rabbit Virology Immunology and Parasitology Unit, France; Université Européenne de Bretagne, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Jestin
mesh_terms: D000818:Animals; D004372:Ducks / Q000821:virology*; D009980:Influenza A virus / Q000472:pathogenicity / Q000502:physiology*; D005585:Influenza in Birds / Q000473:pathology / Q000635:transmission* / Q000821:virology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013047:Specific Pathogen-Free Organisms
keywords: Basic reproduction number (R(0)); H5; Horizontal transmission; Low pathogenic avian influenza; Muscovy ducks