WHO says new bird strain is 'one of most lethal' flu viruses

A new strain of bird flu that has killed 22 people in China is "one of the most lethal" of its kind and is more easily transmissible to humans than an earlier strain that has killed hundreds around the world since 2003, a top World Health Organization (WHO) official said on Wednesday.

The H7N9 virus has infected 108 people in China since it was first detected in March, according to the Geneva-based WHO. Although it is not clear exactly how people have been infected, WHO experts see no evidence so far of the most worrisome scenario - sustained transmission between people. (Reuters)