MELBOURNE, Australia - Deep inside a high-security laboratory an hour from Melbourne, scientists working behind air-locked doors inject six-week-old chickens with a virus that has killed one in five people it’s known to have infected.
The pathogen is H7N9 bird flu, and it came to Australia’s second-biggest city 12 days ago in a 0.5 milliliter sample - 10 would fit on a teaspoon - from a patient in China’s Anhui province. Antibodies from the chickens will help create tests for the virus, part of a race to head off a global outbreak.
While disease trackers have yet to pinpoint how the 127 human infections in China and Taiwan occurred, they say contact with poultry is the most likely cause. Birds carry the disease without showing symptoms, making tests to monitor farms and markets vital to halting its spread, said Peter Daniels, assistant director of the Australian Animal Health Laboratory.
“If one in five people getting infected die, that’s a pretty frightening infection,” said Daniels, 64, whose lab is the world’s largest high-security bio-containment research facility. “It may be that it won’t start spreading person to person. But if it does, the world is facing a severe disease situation.”
An earlier bird flu strain known as H5N1, first isolated from a farmed goose in China’s Guangdong province in 1996, has infected wild birds and domestic poultry in more than 60 countries over the past decade. That virus, which killed 60 percent of the 628 people known to have been infected, doesn’t spread efficiently from human to human. That’s unlike a novel swine flu virus known as H1N1 that emerged in Mexico in 2009 and spread worldwide in months.
Wild birds are the primary natural reservoir for influenza viruses capable of causing pandemics, according to the Centers for Disease Control and Prevention in Atlanta. The 1918 Spanish Flu pandemic, which killed as many as 50 million people, began when an avian flu virus jumped to people who had no immunity to the new strain, doctors say.
H7N9 isn’t known to have infected humans before, so no one has immunity to it. Drugmakers including Melbourne-based CSL and Beijing-based Sinovac Biotech have started to prepare for the possible need to make immunizations, which would be triggered by widespread human-to-human infections in multiple regions.
H7N9 has already moved outside mainland China. Last week, officials in Taiwan reported a case in a 53-year-old man who had just returned to Taiwan via Shanghai after a business trip to the eastern city of Suzhou. The man is in critical condition, doctors said. Government officials in Yokohama, on the outskirts of Tokyo, are testing wild birds for avian flu after 17 crows and a pigeon were found dead, Yomiuri Shimbun said yesterday.
In the past week, the Australian Animal Health Laboratory dispatched samples of the virus’s genetic material to Indonesia and Vietnam as reagents for tests that can detect the H7N9 virus in tissue specimens, which would indicate acute infection, Daniels said.