Cloacal, oropharyngeal and faecal (environmental) swabs were tested using polymerase chain reaction (PCR) for the AI type A matrix gene.
Positive samples underwent virus culture and subtyping.
Serum samples were analysed using a blocking enzyme-linked immunosorbent assay for influenza A virus nucleoprotein.
Results: No highly pathogenic AI viruses were identified. However, 164 PCR tests were positive for the AI type A matrix gene, 46 of which were identified to subtype.
A total of five viruses were isolated, three of which had a corresponding positive PCR and subtype identification (H3N8, H4N6, H7N6).
Low pathogenic AI H5 and/or H7 was present in wild birds in New South Wales, Tasmania, Victoria and Western Australia.
Antibodies to influenza A were also detected in 15.0% of the birds sampled.
Conclusions: Although low pathogenic AI virus subtypes are currently circulating in Australia, their prevalence is low (1.0% positive PCR).
Surveillance activities for AI in wild birds should be continued to provide further epidemiological information about circulating viruses and to identify any changes in subtype prevalence.
Source: Haynes, L., Arzey, E., Bell, C., Buchanan, N., Burgess, G., Cronan, V., Dickason, C., Field, H., Gibbs, S., Hansbro, P., Hollingsworth, T., Hurt, A., Kirkland, P., McCracken, H., O’Connor, J., Tracey, J., Wallner, J., Warner, S., Woods, R. and Bunn, C. (2009), Australian surveillance for avian influenza viruses in wild birds between July 2005 and June 2007. Australian Veterinary Journal, 87: 266–272. doi: 10.1111/j.1751-0813.2009.00446.x
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