No highly pathogenic avian influenza detected

10 October 2006

No highly pathogenic avian influenza detected in first round of national surveillance

Biosecurity New Zealand has completed its first survey of commercial broiler and layer farms throughout the country and found no highly pathogenic avian influenza.

The study was the first phase of an ongoing surveillance programme. MAF will continue to conduct further surveillance to meet its originally stated objectives of confirming the absence of highly pathogenic influenza virus in New Zealand and meeting New Zealand’s international reporting obligations.

New Zealand is part of a global network contributing to knowledge about avian influenza and early warning and detection of highly pathogenic avian influenza. In May this year, Biosecurity New Zealand announced it was increasing surveillance to demonstrate New Zealand’s freedom from highly pathogenic avian influenza.

“This survey supports what more than 30 years of surveillance has told us - that New Zealand does not have highly pathogenic avian influenza,” said Surveillance Principal Adviser, Ron Thornton.

There are many strains of avian influenza viruses, which are naturally present in many species of healthy wild birds, especially water fowl. 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 an Asian strain of the H5N1 type. No H5N1 virus has ever been found in New Zealand.

“The situation in New Zealand remains unchanged – the risk of highly pathogenic avian influenza entering New Zealand in birds is low, and we will be continuing to confirm this fact by conducting surveillance in migratory birds as they arrive in New Zealand.”

Phase one of the comprehensive surveillance programme looked at commercial broiler and layer flocks. A statistically-valid survey was designed in accordance with international guidelines using sensitive serological screening tests. Testing was carried out at Biosecurity New Zealand’s Investigation and Diagnostic Centre at Wallaceville.

Planning is underway for phase two of the ongoing surveillance programme, which will continue to survey some sectors of the commercial industry and migratory wild bird populations.

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 virus have previously been found to exist in our wild bird populations.

Surveillance Principal Adviser, Ron Thornton says that as we increase surveillance, we may find further evidence of low pathogenic viruses but these in themselves are of little concern.

“In the unlikely event that highly pathogenic avian influenza virus was found in New Zealand, Biosecurity New Zealand would move immediately to eradicate the virus. New Zealand is well prepared to respond to an outbreak of avian influenza,” Dr Thornton said. “There are comprehensive response plans and policies in place for avian influenza.”

ENDS

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