title: Epidemiology of avian influenza in wild aquatic birds in a biosecurity hotspot, North Queensland, Australia.
abstract: Migratory birds may introduce highly pathogenic H5N1 avian influenza from Southeast Asia into Australia via North Queensland, a key stopover along the East Asian-Australasian Flyway, with severe consequences for trade and human health. A 3-year repeated cross sectional study on the epidemiology of avian influenza in Australian nomadic wild aquatic birds was conducted in this potential biosecurity hotspot using molecular and serological techniques. Avian influenza virus subtypes H6 and H9 were commonly present in the studied population. It is likely that one of the H6 viruses was newly introduced through migratory birds confirming the perceived biosecurity risk. The matrix gene of another H6 virus was similar to the Australian H7 subtypes, which suggests the reassortment of a previously introduced H6 and local viruses. Similarly, a H9 subtype had a matrix gene similar to that found in Asian H9 viruses suggesting reassortment of viruses originated from Australia and Asia. Whilst H5N1 was not found, the serological study demonstrated a constant circulation of the H5 subtype in the sampled birds. The odds of being reactive for avian influenza viral antibodies were 13.1(95% CI: 5.9-28.9) for Pacific Black Ducks over Plumed Whistling Ducks, highlighting that some species of waterfowl pose a greater biosecurity risk. Antibody titres were slightly higher during warm wet compared with warm dry weather. Routine surveillance programmes should be established to monitor the introduction of avian influenza viruses from Asia and the interactions of the introduced viruses with resident viruses in order to better detect emerging pathogens in aquatic birds of North Queensland. Surveillance should be targeted towards highly susceptible species such as the Pacific Black Duck and carried out during favourable environmental conditions for viral transmission such as the wet season in northern Australia.
authors.affiliation: School of Veterinary and Biomedical Science, James Cook University (JCU), Townsville QLD 4811, Australia; School of Public Health, Tropical Medicine and Rehabilitation Sciences, JCU, Townsville QLD 4811, Australia; Faculty of Veterinary Medicine, Chittagong Veterinary and Animal Sciences University, Khulshi, Chittagong 4225, Bangladesh. Electronic address: md.hoque@my.jcu.edu.au.
authors.forename: Md Ahasanul
authors.initials: MA
authors.lastname: Hoque
authors.affiliation: School of Veterinary and Biomedical Science, James Cook University (JCU), Townsville QLD 4811, Australia.
authors.forename: Graham William
authors.initials: GW
authors.lastname: Burgess
authors.affiliation: School of Veterinary and Biomedical Science, James Cook University (JCU), Townsville QLD 4811, Australia.
authors.forename: Ai Lee
authors.initials: AL
authors.lastname: Cheam
authors.affiliation: School of Public Health, Tropical Medicine and Rehabilitation Sciences, JCU, Townsville QLD 4811, Australia.
authors.forename: Lee Francis
authors.initials: LF
authors.lastname: Skerratt
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001717:Birds; D002988:Cloaca / Q000821:virology; D003430:Cross-Sectional Studies; D030561:Databases, Nucleic Acid; D004372:Ducks / Q000821:virology; D053124:Influenza A Virus, H5N1 Subtype; D005585:Influenza in Birds / Q000097:blood / Q000453:epidemiology* / Q000235:genetics* / Q000276:immunology; D015233:Models, Statistical; D009960:Oropharynx / Q000821:virology; D010802:Phylogeny; D011793:Queensland / Q000453:epidemiology; D012328:RNA Viruses / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D012307:Risk Factors
chemical_list: D000914:Antibodies, Viral
keywords: Australian nomadic wild aquatic birds; Avian influenza; Epidemiology; North Queensland