Chinese officials have closed poultry markets and ordered a mass slaughter of birds in Shanghai amid an outbreak of a type of avian flu that has not been seen in humans.

As of Friday, six people out of an apparent 14 who have been infected with H7N9 have died, a mortality rate of nearly 50 percent, the World Health Organization said in a statement. The cases reportedly occurred in eastern China.

The WHO says there is no evidence of the possibility of human-to-human transmission. Mayo Clinic flu expert Dr. Gregory Poland told MedPage Today that there seems to be little connection among the victims.

“We know the professions of the individuals that have been infected,” he told the site. With one exception they appear to have had little or no contact with birds or poultry. “There doesn’t seem to be any common connection between these individuals, which is a little worrisome, nor does there appear to be a common source for the outbreak,” he continued.

Poland noted that tracing of the early patients’ contact with others found no sign that any friends, relatives or co-workers were infected.

— Posted by Alexander Reed Kelly.

BBC:

“We have 14 cases in a large geographical area, we have no sign of any epidemiological linkage between the confirmed cases and we have no sign of sustained human-to-human transmission,” WHO spokesman Gregory Hartl said in Geneva.

The latest fatality was a farmer, 64, who died in Zhejiang province, state-run media say.

Four of the bird flu fatalities and six of the 14 cases have been recorded in Shanghai.

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