China has announced a sixth death from a new bird flu strain, while authorities in Shanghai halted the sale of live fowl and slaughtered all poultry at a market where the virus was detected in pigeons being sold for meat.
The mass bird killing is the first so far as the Chinese government responds to the H7N9 strain of bird flu, which has sickened 16 people, many critically, along the eastern seaboard in its first known infections of people. The first cases were announced on Sunday, while the two latest cases are both pensioners, 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 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 after the city's agricultural committee ordered it in a notice also posted on its website.
State media are running 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, a city spokesman said.
Pigeon is a common type of poultry in Chinese cuisine and the birds are sold live in markets around the country. Chinese also raise pigeons as pets, but those tend to be a different type.
The latest death from the virus confirmed by the government was a 64-year-old farmer in the eastern city of Huzhou. Authorities said the virus also killed a 48-year-old man who transported poultry for a living and a 52-year-old woman, both in Shanghai. Several among the infected are believed to have had direct contact with fowl.