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Tuesday, April 30, 2013

Scientists Infect Chicks in Race to Halt Bird Flu Spread


By Jason Gale - Apr 30, 2013 7:06 PM 

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.
Scientists conduct research at the Australian Animal Health Laboratory (AAHL) in Geelong, Australia. The center received on April 19 a half a milliliter specimen of the H7N9 virus taken from a patient in China’s Anhui province. Source: CSIRO via Bloomberg
A scientist conducts tests inside an air-locked chamber in a biosecurity level-3 area of the Australian Animal Health Laboratory (AAHL) in Geelong, Australia on April 30, 2013. Photographer: David Williams/CSIRO via Bloomberg
“If one in five people getting infected die, that’s a pretty frightening infection to be confronted with,” said Dr. Peter Daniels, assistant director of the Australian Animal Health Laboratory (AAHL). “It may be that it won’t start spreading person to person. If it does, the world is facing a severe disease situation.” Source: CSIRO via Bloomberg
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 inMexico in 2009 and spread worldwide in months.

1918 Pandemic

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-basedCSL Ltd. (CSL) and Beijing-based Sinovac Biotech Ltd. (SVA) have started to prepare for the possible need to make immunizations, which would be triggered by widespread human-to-human infections in multiple regions.

Dead Crows

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, or AAHL as its known locally, dispatched samples of the virus’s genetic material to Indonesia and Vietnam as reagents for tests that can detect H7N9 viral material in tissue specimens, which would indicate acute infection, Daniels said. Three more countries will receive specimens this week, with further shipments planned.
Opened in 1985 by the Australian government, AAHL looks like an enormous, grey-concrete bunker. Its six floors have 65,000 square meters (700,000 square feet) of space, a labyrinth of laboratories and animal enclosures. The only windows to the outside are in the cafeteria. The building was designed to operate for 100 years, withstanding 1-in-10,000-year natural disasters such as 300 kilometer-per-hour winds and magnitude 5.8 earthquakes.

Kate Winslet

Its research on disease-causing microbes such as the Nipah and Hendra viruses earned it a mention in the 2011 movie “Contagion” starring Matt Damon and Kate Winslet.
The H7N9 antibodies are being raised in the center’s Diagnostic Emergency Response Laboratory, opened five years ago in a part of the building once used for bottle-washing. It can process 10,000 antibody tests and 1,000 genetic tests a day, Daniels said. Inside the secure building lab, capable of safely handling the most lethal and virulent biological agents known to mankind, the H7N9 virus is replicated in sterile, fertilized hen’s eggs inside an air-locked chamber.
The lab is also producing antisera -- blood serum containing antibodies -- against H7N9 in ferrets for the World Health Organization. The material will be used to assist in identifying infections in people, said Ian Barr, deputy director of the WHO’s Collaborating Center for Reference and Research on Influenza in Melbourne.

Commercial Flight

That center, on the fringe of Melbourne’s downtown, was the original destination for the specimen from China. After being transported on a commercial flight from Beijing in a tightly packed vial inside a sealed foam carton, the virus was replicated in 15 eggs before samples were sent to Daniels’ lab three days later, Barr said.
“It grows very well, this virus,” Barr said.
The ferret research will help public health officials understand the new virus’s ability to cause disease in mammals, and to determine whether it spreads via direct contact alone or can be transmitted by coughing and sneezing.
Early indications from experiments with ferrets in the U.S. suggest that infections caused by the virus aren’t as severe as those from the H5N1 bird flu strain, typically not extending beyond the respiratory tract, Barr said, adding that more research is needed to validate the findings. Antisera collected from the ferrets will help scientists determine whether H7N9 is undergoing important genetic changes, he said.
“We need to remain very vigilant,” Barr said. “It’s still on the precipice of potentially tipping over from isolated animal-human infections to something more serious.”http://www.bloomberg.com/news/2013-04-30/scientists-infect-chicks-in-race-to-halt-bird-flu-spread.html