Hong Kong reported its first case of a form of bird flu that killed 45 people in eastern China, suggesting the virus is spreading further south in poultry.
A 36-year-old Indonesian domestic helper is in critical condition after being infected with the new H7N9 flu strain, Hong Kong’s government said yesterday.
She had traveled to the neighboring city of Shenzhen, where she bought and slaughtered a chicken, according to a statement.
Her infection suggests the virus, which is often lethal to humans, but causes no symptoms in birds, is circulating less than 48km from downtown Hong Kong.
The territory’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.
“Respiratory viruses do their own thing; they don’t respect boundaries,” Ian Mackay, an associate professor of clinical virology at the University of Queensland in Brisbane, Australia, said by telephone. “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.”
Four people who had been in recent close contact with the patient are displaying minor symptoms, Hong Kong Food and Health Bureau Secretary Ko Wing-man (高永文) said in the statement. Authorities are still locating the patient’s travel companion to Shenzhen, he said.
Hong Kong Department of Health spokesman Chris Cheung declined to elaborate on the circumstances around which the patient was probably infected. The patient visited Shenzhen on Nov. 17, according to the statement.
She had a history of “traveling to Shenzhen, buying a chicken, slaughtering the chicken and eating the chicken,” Ko told reporters.
Shenzhen is a 61-minute train ride from the downtown Central district of Hong Kong and a popular day-trip destination for shopping and dining.
Last year, Hong Kong residents departed from the Lo Wu check point 35.4 million times, according to the census and statistics department.
“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.
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 Suzhou, China.
Technical difficulties in detecting H7N9 infections may be causing cases to go unreported, Cowling said.
Residents of Guangdong Province, which borders Hong Kong, appear to have a greater preference for buying live poultry than those of other provinces, he said.
Shanghai is to suspend live poultry trading from Jan. 31 next year, the first day of the Lunar New Year, until April 30 to prevent a recurrence of the bird flu, Xinhua news agency reported.
Hong Kong’s government has suspended the importation of live chickens from three Shenzhen farms, according to the statement.
Hong Kong officials will visit poultry farms and live chicken stalls in markets to ensure compliance.
“The big thing is if animal contact and the slaughtering of animals can be minimized, the risk of infection is going to be reduced,” Mackay said. “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.”