Shanghai has reported two more cases of human infection of a new strain of bird flu, raising the number of cases in eastern China to 18. Six of the people who contracted the virus have died.
Health officials believe people are contracting the H7N9 virus through direct contact with infected fowl and say there's no evidence the virus is spreading easily between people.
Shanghai's government said Saturday the latest victims are a 74-year-old peasant and a 66-year-old retiree. The city has been ordered by the agriculture ministry to halt its live poultry trade and slaughter all fowl in markets where the virus has been found.
The capital cities of the neighbouring provinces of Zhejiang and Jiangsu also have suspended sales of live poultry. Both provinces have reported H7N9 cases.
The mass bird killing is the first so far as the Chinese government responds to the H7N9 strain of bird flu, which has sickened 18 people, many critically, along the eastern seaboard in its first known infections of people. The first cases were announced Sunday, while two more were reported Friday, both retirees who were seriously ill.
Health officials believe people are contracting the virus through direct contact with infected fowl and say there has been no evidence so far that the virus is spreading easily between people. However, scientists are watching closely to see if the flu poses a substantial risk to public health or could potentially spark a global pandemic.
The Agriculture Ministry confirmed on Thursday that the H7N9 virus had been detected in live pigeons on sale at a produce market in Shanghai. The killing of birds at the Huhuai market in Shanghai started Thursday night after the city's agricultural committee ordered it in a notice also posted on its website.
State media on Friday ran pictures of animal health officials in protective overalls and masks working through the night at the market, taking notes as they stood over piles of poultry carcasses in plastic bags. The area was guarded by police and cordoned off with plastic tape.
Experts urged Chinese health authorities to keep testing healthy birds, saying the H7N9 virus can infect birds without causing them to become ill, making it harder to detect than the H5N1 bird flu virus that is more familiar to Asian countries. H5N1 set off warnings when it began ravaging poultry across Asia in 2003 and has since killed 360 people worldwide, mostly after close contact with infected birds.
"In the past usually you would see chickens dying before any infections occurred in humans, but this time we've seen that many species of poultry actually have no apparent problems, so that makes it difficult because you lose this natural warning sign," said David Hui, an infectious diseases expert at the Chinese University of Hong Kong.
The city of Shanghai also announced a suspension of the sale of live poultry starting Saturday.