BLOOMBERG
By Natasha Khan & Joshua Fellman
12/03/2013
Her infection suggests the virus, which is often lethal to humans but causes no symptoms in birds, is circulating less than 30 miles from downtown Hong Kong. The city’s government curbed live poultry sales 16 years ago to prevent an earlier bird-flu variant from spreading. Yesterday, it elevated the response level under its influenza pandemic preparedness plan to “serious,” requiring hospitals to step up infection controls and limit visiting hours.
“We might not expect that this case is the only infection” in Shenzhen, said Ben Cowling, associate professor of infectious disease epidemiology at the University of Hong Kong’s School of Public Health.
Four people who had been in recent, close contact with the patient are displaying minor symptoms, said Ko Wing-man, the city’s health secretary, in the statement. Results of diagnostic tests on them and others may be available as early as today.
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Virus weaponizers Kawaoka and Fouchier |
She had a history of “traveling to Shenzhen, buying a chicken, slaughtering the chicken and eating the chicken,” Ko told reporters in Hong Kong yesterday.
Market Closures
Human cases of H7N9 in China date back to February and surged in April before agriculture authorities temporarily closed live poultry markets and quarantined farms to limit human exposure. The Geneva-based World Health Organizationcounted 137 laboratory-confirmed cases as of Oct. 25.
“Respiratory viruses do their own thing; they don’t respect boundaries,” said Ian Mackay, an associate professor of clinical virology at the University of Queensland in Brisbane, Australia, in a telephone interview. “It does seems that it’s continuing to add to provinces and regions, rather than reappear in all the old places it started in back in February and March.”
H7N9 has previously turned up outside mainland China. In late April, 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.
Fondness for Fresh
Technical difficulties in detecting H7N9 infections may be causing cases to go unreported, Cowling said. Residents of Guangdong, the Chinese province bordering Hong Kong, appear to have a greater preference for buying live poultry than those of other provinces, he said.
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Ernala-Ginting (2d from left), Kawaoka and Kobe lab staff |
To control an outbreak of H5N1 in 1997, Hong Kong authorities culled about 1.5 million chickens to remove the source of the virus. The order was made byMargaret Chan, then Hong Kong’s director of health, who is now WHO director-general in Geneva. The measure later became the global standard for the control of avian influenza.
Rusty Cages
Many families in rural areas kept chickens in their yards in wood-and-wire hutches that can still be seen lying empty and rusting in villages across the territory. Ducks, geese and pigeons are also widely eaten in Hong Kong.
Detection of H7N9 has been complicated by the fact that chickens and ducks don’t get sick from the virus.
Shanghai will suspend live poultry trading from January 31, the first day of the Chinese New Year, until April 30 to prevent a recurrence of the bird flu, the official news agency Xinhua reported yesterday. Hong Kong’s government has suspended the importation of live chickens from three Shenzhen farms, according to yesterday’s statement.
Hong Kong officials will visit poultry farms and live chicken stalls in markets to ensure compliance.
The city’s government said it has notified mainland health authorities and WHO about the confirmed infection.
“The big thing is if animal contact and the slaughtering of animals can be minimized, the risk of infection is going to be reduced,” said the University of Queensland’s Mackay. “If markets could be shut down or changed in the way they work, I’m sure the spread of H7N9 would take the same sort of dive that it did earlier in the year.”
To contact the reporters on this story: Joshua Fellman in New York at jfellman@bloomberg.net; Natasha Khan in Hong Kong at nkhan51@bloomberg.net
To contact the editor responsible for this story: Jason Gale at j.gale@bloomberg.net