Avian influenza has caused its first confirmed mass death event in Australian wildlife. Aerial surveillance crews counted 49 dead greater crested terns and 35 more showing acute signs of illness at Baudin Rocks, an offshore islet near Robe on South Australia's Limestone Coast. Testing confirmed H5N1.
It is the largest single-site count since the virus reached the country in June. Environment Minister Murray Watt and Agriculture Minister Julie Collins confirmed the result on Monday.
“I want to level with people: this is the beginning of what is likely to be a long, difficult journey," Watt said.”
Collins said the spread through wildlife is now past the point where losses can be avoided. "Australians should expect to see more spread and larger numbers now of wildlife being affected," she said.
There were 74 confirmed cases nationally as of Monday: 54 in South Australia, 10 in Western Australia, seven in Victoria, two in New South Wales and one in Queensland. Samples go to the CSIRO Australian Centre for Disease Preparedness at Geelong for confirmatory testing, and the national count moves as those results come back.
Nothing has been detected in poultry or other livestock. Producers locked their flocks down after the first mainland detection in mid-June, a brown skua found at Cape Le Grand National Park near Esperance in Western Australia. Silver gulls have since tested positive, as have Australian sea lions, including five at Seal Bay on Kangaroo Island.
South Australia's chief veterinary officer, Skye Fruean, said transmission through wild birds cannot be stopped, and that the detections show the surveillance program working as designed. The terns at Baudin Rocks were found from a helicopter.
Authorities rate the risk to human health as low. H5N1 can infect people who have close contact with infected animals, and the number of confirmed human cases worldwide is small.
Until June, Australia was the only continent without H5N1. The virus arrived after years of spread everywhere else, which gave governments here a long window to prepare. New Zealand spent part of it vaccinating birds. Its Department of Conservation has run an H5N1 vaccine trial for two years across six species, among them the kakapo, of which fewer than 300 remain, and the South Island takahe, at about 500. It has vaccinated 196 of the 300 birds it is targeting.
Australia's preparation went into watching rather than into vaccine. Kirsty Short, a virologist at the University of Queensland, has called the surveillance program world-class and says no other country has documented its cases as thoroughly. She has also said Australia went into the outbreak without the research on native species that would tell anyone how those species will fare. Patrick Finnerty at the University of Sydney puts it more bluntly: ask how the disease will move through a given Australian animal and the answer is usually that nobody knows.
Neither minister put a number on the losses to come. Both said the poultry sector remains the line the response is built to hold, and it has held so far.
