HONG KONG (CNN) -- The death toll in China's bird flu crisis stood at 10 on Friday, as Hong Kong authorities announced plans to test all poultry imported from the mainland.
A 74-year-old man died on Thursday afternoon in Shanghai after first being diagnosed with pneumonia and then testing positive for the H7N9 avian influenza virus on Wednesday night, the state-run Xinhua news agency reported.
He was one of three new infection cases diagnosed in the city, as the total number of cases across eastern China climbed to 38, Xinhua said. The other two patients -- an 83-year-old woman and a 68-year-old man -- are in a stable condition in hospital.
Seventy people have had close contact with the three patients, but none of them have exhibited abnormal symptoms, according to a statement from the Shanghai Municipal Health and Family Planning Commission, cited by Xinhua.
The World Health Organization (WHO) and Chinese health officials continue to monitor for human-to-human transmission.
While the source of the infection is unknown, poultry markets have become the focus of the investigation by China's health ministry and the WHO. The virus had been known to affect pigeons but had not previously been discovered in humans until a series of cases were reported in China last week.
On Wednesday, the Chinese Academy of Sciences said the H7N9 virus had probably originated from migratory birds from East Asia mixing with domestic fowl in China's Yangtze River delta region.
A number of cities across eastern China have suspended trading in live poultry in an effort to contain the problem.
On Friday, Hong Kong's Food and Environmental Hygiene Department announced that poultry imported from companies in Mainland China would be subjected to "fast tests" for the H7N9 and H5N1 strains of the virus.
According to a statement, "Officers will randomly select 30 birds from each consignment of around 1,000 (birds), to collect swabs and blood samples for the rapid test detecting the H5 and H7 antigen and antibodies."
Results will available within four to five hours, with cleared poultry then taken to a temporary wholesale market in the city for sale.
"When there are birds infected by H7 or H5, all the import of poultry will be suspended according to the World Organization for Animal Health's recommendations," said Allen Chan, senior veterinary officer with the city's health department.
The current outbreak has started to take its toll economically, after Yum Brands, the parent company of KFC in China, warned this week that sales at its restaurants across the country had suffered a sharp fall.
Xinhua also reported that the price of poultry had fallen by up to 50% in some eastern cities in the past week, hitting farmers. Shanghai has now completely banned the sale of life poultry.
-- CNN's Pamela Boykoff in Hong Kong and Ke Feng in Beijing contributed to this report.
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