Freedom from avian influenza
DATE 17 May 2006
Increased surveillance to demonstrate freedom from avian influenza
Biosecurity New Zealand is increasing surveillance for avian influenza to meet new World Organisation for Animal Health (OIE) reporting requirements and demonstrate New Zealand’s freedom from highly pathogenic avian influenza.
New Zealand is part of a global network contributing to the knowledge on avian influenza and early warning and detection of highly pathogenic avian influenza.
A comprehensive surveillance programme will survey all bird compartments: layer flocks, broiler flocks, breeder chicken flocks, backyard chicken flocks, ratites, farmed ducks and geese, game birds and wild birds. Biosecurity New Zealand has been working with the poultry industry to put in place the most effective surveillance strategy. Phase one of the programme will conduct surveillance for avian influenza in layer and broiler flocks.
“The situation in New Zealand is unchanged - the risk of highly pathogenic avian influenza entering the country in birds remains low,” said Team Manager Surveillance and Incursion Response Ron Thornton. “We are increasing surveillance activity for avian influenza in birds to meet OIE reporting requirements. This will provide the evidence needed to demonstrate New Zealand’s freedom from avian influenza to the OIE”.
“This is an extension of the ongoing surveillance programme we already have in place. Our international reporting commitments mean that more avian influenza surveillance is needed,” Dr Thornton said.
There are many strains of avian influenza viruses, which are naturally present in many species of healthy wild birds, especially water fowl. Most strains of avian influenza virus do not cause disease in birds and are not of human health concern.
Strains of avian influenza are categorised as highly pathogenic or of low pathogenicity on the basis of the severity of clinical signs in chickens. Low pathogencity avian influenza viruses may cause mild or no clinical disease in birds, but are harmless to humans. The highly pathogenic avian influenza virus of worldwide concern at present is the H5N1 strain. This is because of the number of countries affected at the same time, the level of human exposure due to the size of the outbreaks, and the wider range of birds including wild ducks and geese, and also mammals, affected.
Biosecurity New Zealand has been monitoring arriving migratory shorebirds since 1984. No highly pathogenic avian influenza virus has ever been found in New Zealand, but strains of milder low pathogenicity avian influenza have been found to exist in our wild bird populations. About 3500 samples have been taken from wild birds in New Zealand since 1976. Only three low pathogenic notifiable avian influenza viruses have been found. All three are harmless to birds and humans.
“New Zealand is well prepared to respond to an outbreak of avian influenza,” Dr Thornton said, and has comprehensive response plans and policies in place for avian influenza. In the unlikely event that highly pathogenic avian influenza virus is found in New Zealand, Biosecurity New Zealand will move immediately to eradicate the virus. If any strains of low pathogenicity avian influenza viruses are found, Biosecurity New Zealand will seek independent technical advice and assess appropriate response options.