WHO Puzzled by Deadly Chinese Bird-Flu Strain

A World Health Organization team of researchers is in China, trying to determine how a new strain of bird flu, H7N9, spreads. Human-to-human transmission would be dangerous, and researchers are investigating family members who share the flu strain. “So far, investigators have said they can't rule out limited person-to-person transmission, which could include unusually close contact, such as exposure to bodily fluids,” reports Esther Fung for the Wall Street Journal. “By contrast, sustained human-to-human transmission could include proximity and casual contact, such as with the common flu.” The US has started to develop a synthetic vaccine based on information that China and WHO have posted online. WHO and Chinese health officials have not yet made a decision on developing a vaccine just yet. Developing a flu vaccine can take up to six months. So far, H7N9 has infected more than 100 in China. – YaleGlobal

WHO Puzzled by Deadly Chinese Bird-Flu Strain

At China’s invitation, WHO researchers investigate patients with H7N9 flu to determine if human-to-human transmission is a possibility
Esther Fung
Monday, April 22, 2013

SHANGHAI: The World Health Organization has only a limited understanding of a deadly new form of avian flu that has killed 20 people and infected more than a hundred others, a team of researchers said on Monday, leaving unclear how the disease spreads and how virulent it could become.

The team, which is in China to study the strain of bird flu called H7N9, said they found no evidence of sustained human-to-human transmission, which could make the disease more contagious and more dangerous. But it said it was still exploring the possibility of limited transmission via humans, given the presence of small clusters of infections.

"The same question has been looked by the [local] investigators as well as by ourselves, and I think that we don't know the answer," Keiji Fukuda, the WHO's assistant director general for health security and environment, told a news conference on Monday, adding that the situation "remains complex and difficult."

"It is virtually impossible to predict how many more cases" could appear, he said, though he added that "it is important to recognize that if the infection spreads a little bit, it doesn't mean that things are out of control."

The WHO team, which was invited to visit China by national health authorities, spent the weekend inspecting medical facilities and sites in Shanghai, the largest single locale for the outbreak. Most of the infections have been in eastern China, though those in central Henan province and in Beijing suggest the disease has the potential to spread.

Chinese and international investigators are probing how easily the disease could spread from person to person. So far, investigators have said they can't rule out limited person-to-person transmission, which could include unusually close contact, such as exposure to bodily fluids. By contrast, sustained human-to-human transmission could include proximity and casual contact, such as with the common flu.

"So far, we still have limited knowledge of the virus…but we are certain that the virus is constantly changing," said Yang Weizhong, vice director at the Chinese Center for Disease Control and Prevention, at the news conference.

In Shanghai, there have been at least two cluster cases, one involving a father and two sons and the other a husband and wife. "Were they exposed to the same thing?" Dr. Fukuda said. "It could have been an infected animal, it could have been the environment, and we're always looking for that. And we also ask ourselves, is it possible that there was a transmission between the two people who were sick?"

Dr. Fukuda noted many of the victims were older. Of the 63 cases of H7N9 reported between the first notice of the outbreak on March 31 and April 16, 62% of those infected were 60 years old or older, the WHO said, citing Chinese data.

Health authorities in China say they don't know exactly how the virus is spreading but believe it crossed from birds to humans. As a result, they have undertaken mass poultry culls in several cities.

The WHO and Chinese health officials said they haven't made a decision to develop a vaccine yet. A vaccine could take four to six months to develop, Dr Fukuda said.

The WHO team included many of the world's top bird-flu experts, including Dr. Fukuda and Malik Peiris, of the University of Hong Kong's School of Public Health, WHO officials said previously.

 

Josh Chin contributed to this article.

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