The death toll from the new strain of bird flu sickening people in eastern China has risen to five, the two latest deaths coming in Shanghai.
Chinese officials confirmed the death Thursday of a 48-year-old man who transported poultry for a living. The other victim was not identified.
Chinese officials have identified 14 cases of the H7N9 virus, which until recently had not been known to affect humans.
Chinese medical experts say it is not clear how people are getting infected since the virus apparently cannot be transmitted from person to person. Authorities in Shanghai Thursday said they found the virus in a sample taken from a pigeon at a traditional market.
The new strain of bird flu has officials worried. The U.S. Centers for Disease Control and Prevention says it is following the situation closely and is developing a vaccine as a precaution.
Concerns are also spreading across Asia. Authorities in Hong Kong are monitoring poultry farms and suspending the live bird exports from mainland China. In Japan, airline passengers from China are being asked to report any influenza-like symptoms.
OPTIONAL SOUND BITES
TIMOTHY O'LEARY, WORLD HEALTH ORGANIZATION WESTERN PACIFIC REGIONAL OFFICE PUBLIC INFORMATION OFFICER:
"This is a very unique event. H7N9 had not been known previously to infect human beings. We'd seen it before only in birds. So for this virus suddenly to turn up in humans is a great cause for concern.''
YOSHIHIDE SUGA, JAPANESE CHIEF CABINET SECRETARY (IN JAPANESE):
"I have told the Health Minister to take all possible measures in our response to this virus, bringing together every shred of available information and keeping the Japanese people informed of where it leads.''
LAURIE GARRETT, SENIOR FELLOW FOR GLOBAL HEALTH AT COUNCIL FOR FOREIGN RELATIONS:
"We need to know how are these people getting infected. Who are they getting it from? We need to know what's the denominator. How many people out there in China are infected right now with this virus harmlessly or with very mild illness? Third, we need to know what species did this come from. Did it come from birds? Did it come from dead pigs? Did it come from other animals of some kind? Until we have those three big questions answered, we have no capacity to speculate about the probability that this will become the next great pandemic.''