Incidence and risk factors for H5 highly pathogenic avian influenza infection in flocks of apparently clinically healthy ducks.
A prospective longitudinal study was conducted on 96 smallholder duck farms in Indonesia over a period of 14 months in 2007 and 2008 to monitor bird- and flock-level incidence rates of H5 highly pathogenic avian influenza (HPAI) infection in duck flocks, and to identify risk factors associated with these flocks becoming H5 seropositive. Flocks that scavenged around neighbouring houses within the village were at increased risk of developing H5 antibodies, as were flocks from which carcases of birds that died during the 2 months between visits were consumed by the family. Duck flock confinement overnight on the farm and sudden deaths of birds between visits were associated with lower risk of the flock developing H5 antibodies. Scavenging around neighbouring houses and non-confinement overnight are likely to be causal risk factors for infection. With this study we have provided insights into farm-level risk factors of HPAI virus introduction into duck flocks. Preventive messages based on these risk factors should be included in HPAI awareness programmes.
School of Veterinary Science, The University of Queensland, Gatton, QLD, Australia.
J
J
Henning
Jemora Pty Ltd, PO Box 2277, Geelong, VIC, Australia.
J M
JM
Morton
School of Veterinary Science, The University of Queensland, Gatton, QLD, Australia.
H
H
Wibawa
Disease Investigation Centre Regional IV Wates, Jl. Raya Yogya-Wates KM 27, Yogyakarta, Indonesia.
D
D
Yulianto
Disease Investigation Centre Regional IV Wates, Jl. Raya Yogya-Wates KM 27, Yogyakarta, Indonesia.
T B
TB
Usman
Disease Investigation Centre Regional IV Wates, Jl. Raya Yogya-Wates KM 27, Yogyakarta, Indonesia.
W
W
Prijono
Disease Investigation Centre Regional IV Wates, Jl. Raya Yogya-Wates KM 27, Yogyakarta, Indonesia.
A
A
Junaidi
School of Veterinary Science, The University of Queensland, Gatton, QLD, Australia.
J
J
Meers
D000822:Animal Husbandry / Q000379:methods*; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D004372:Ducks / Q000276:immunology / Q000821:virology*; D015994:Incidence; D007214:Indonesia / Q000453:epidemiology; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology / Q000302:isolation & purification*; D005585:Influenza in Birds / Q000097:blood / Q000453:epidemiology*; D016015:Logistic Models; D011446:Prospective Studies; D012372:ROC Curve; D012307:Risk Factors
D000914:Antibodies, Viral