Mapping China's Bird Flu Outbreak

See how H7N9 is spreading.

Today, a 64-year-old man in Huzhou, in Zhejiang province, died of H7N9. Earlier in the day, Shanghai's government closed all poultry markets. Over 20,000 birds have been slaughtered. (China Realtime Report has a great roundup of photos illustrating the crackdown.) And airline shares are falling globally as investors fear people will be reluctant to travel to China.

A seven-year-old Hong Kong girl who visited Shanghai recently is now showing signs  of having contracted the bird flu strain. She is undergoing tests in a Hong Kong hospital. Taiwan, however, seems so far to have staved off the virus, as its Center for Disease Control ruled eight patients who had recently been in China to be in the clear. However, Taiwan is banning those recently returned from the mainland from visiting chicken farms. The annual Tomb Sweeping Festival, which began on Thursday, typically sees increased travel back to the mainland to visit ancestral graves.

All of the other of the 14 reported cases have so far occurred in eastern China.

Some of the latest developments:

April 5, 7:13 a.m. ET: While a sixth avian flu death has just been reported in eastern China, today also saw the first suspected H7N9 cases observed outside mainland China.

April 4, 4:33 p.m. ET: Five people have now died from a rare form of avian flu that has infected nine others, sparked fears of a possible endemic in China, and alarmed public health experts. Authorities in Shanghai, site of all but one of the deaths, began a mass slaughtering (paywall) of poultry after officials said they found the virus, H7N9, in pigeons sold at a local market.

The finding of H7N9 in the pigeons is the first clue as to the source of a virus that has never been known to infect humans before. There is no evidence that the virus can jump between humans, which could spark a pandemic that epidemiologists have long worried about. However, scientists say the gene sequence of the virus suggests it has adapted to mammals and is mutating closer to a form that would be contagious between people. We've reported on how that might have already happened through pigs, thousands of which mysteriously wound up dead in a river near Shanghai last month.

Also worrisome is that most of the cases of H7N9 have been in dense urban areas across several provinces in the southeast of China, suggesting millions of people may have been exposed. "What we're looking at is something very serious, that is transmissible through some fairly ubiquitous means," said Laurie Garrett, a global health fellow at the Council on Foreign Relations, in an interview.

Of the 14 cases, six have been in Shanghai, three in Zhejiang province (where one person has died), four in Jiangsu province, and one in Anhui province. In response to the outbreak, Vietnam and Hong Kong have temporarily banned all poultry imports from China. The World Health Organization says Chinese health authorities are monitoring 400 people who were in contact with those infected.

Here's our take on whether China has gotten better at handling public health crises since 2003 when authorities attempted to cover up a deadly outbreak of the SARS epidemic.