Seven people have died and 24 have been sickened in China from a new strain of bird flu, H7N9. Chinese authorities have ordered the slaughter of 20,000 birds in a live poultry market in Shanghai, after a pigeon with the virus was detected there. So far, no humans have reportedly been infected with the virus by another human, though one person who had been in contact with one of those who died from H7N9 has been quarantined after exhibiting flu-like symptoms.
The victims include a 4-year-old child and 15 adults, including an 87-year-old man in Shanghai. All those who have died became ill between February 19 and March 31 and have had some connection to the poultry markets; the most recent person reported to have died from H7N9 is a 38-year-old chef, surnamed Hong, who worked in Jiangsu (the province next to Shanghai). Chinese officials have been tracking 100 people with close connections to those who became ill and none have become sick yet, NBC reports.
Nonethless, residents of Shanghai displaying any symptoms of flu have been hurrying to emergency rooms and foregoing chicken. The U.S.’s Centers for Disease Control and Prevention is at work developing a vaccine against H7N9.
Should We Be Worried?
As of Monday, April 8, the World Health Organization emphasizes that there is no need for “over-reaction or panic,” Reuters reports.
Caution is certainly understandable in the wake of the outbreak of SARS (severe acute respiratory syndrome), which began about a decade ago in the Chinese province of Guangdong, killed nearly 800 and sickened more than 8,000. Chinese health officials initially sought to cover-up the outbreak, not letting officials from the WHO visit Guangdong for five weeks and then hiding sick patients from WHO officials. This initial secrecy was, according to experts, one reason SARS spread around the globe.
In the case of H7N9, Chinese officials have offered information “relatively quicker,” as The Economist puts it. Users on Sina Weibo, China’s equivalent of Twitter, have been wondering why the government waited two weeks to announce the first two cases in March.
CDC director Thomas R. Frieden has said that Americans planning to go to China should still do so, while following longstanding recommendations to avoid contact with birds and other animals. Certainly, tourists should avoid live poultry markets. Shanghai officials have told residents that eating cooked chicken is all right. The virus seems to respond to other medications (Tamifu, Relenza) for the flu and the WHO says that it is “not advising screening at points of entry or any trade restrictions in connection with the outbreak.”
Scientists Studying H7N9′s Genetic Sequence, Urge Caution
The CDC and its counterpart in China have been working in “close cooperation,” leading to China posting information about the genetic sequence of H7N9 on the GISAID flu sequence database so that researchers can learn “what clues the genome might hold — including the source of the virus, its pathogenicity and its potential to infect, and spread between, humans,” says Nature.
With SARS in mind, scientists are still warning of a potential panic should the H7N9 virus mutate into a form that would allow human-to-human transmission. John Oxford, a professor of virology at Queen Mary, University of London, pointed out that the new bird virus has so far had a “relative high fatality rate” and has been detected in poultry that did not present with other evident signs of illness, notes the New York Times.
Another avian virus, H5N1, has wiped out poultry stocks in southeast Asia and killed some 300 people since 2003. But H5N1 can be controlled by “extensive culling,” says Nature. As Malik Peiris, a flu virologist at the University of Hong Kong, notes, a virus with “few visible symptoms” in birds could be “almost impossible to control”; it might already be too late to wipe such a virus out.
As The Economist describes, the second person to die of the new bird flu was a 27-year-old pork butcher, Wu Liangliang, in Shanghai. His family thought he had pneumonia for 20 days until learning he was listed as having died from H7N9 via a television report. The butcher’s father-in-law, Wu Desen, says he was treated in the same department at the Fifth People’s Hospital, where the flu’s first victim, an 87-old-man surnamed Li, died. Li’s two sons also had flu-like symptoms and one, aged 55, has died and the other recovered; authorities, after not citing H7N9 in their deaths, are reinvestigating.
In light of what we know about SARS and its spread and about recent and growing concerns about the safety of the food supply in China, if you’re traveling there, the CDC’s advice about avoiding birds and other live animals is simply commonsensical. As Peiris emphasizes in Nature, we “should not overreact, but neither should we be complacent.”
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