China on Tuesday said the H7N9 bird flu had spread to a new area as it confirmed the first case in the eastern province of Shandong in an outbreak which has so far killed 22 people. Since China announced on March 31 that the virus had been discovered in humans for the first time, most cases have been confined to the commercial hub Shanghai and three nearby provinces, Jiangsu, Zhejiang and Anhui. Beijing and the central province of Henan have also reported cases.

A top WHO influenza expert said Monday there was still no evidence H7N9 bird flu was spreading in a "sustained" way between people in China, despite the possibility some family members may have infected one another. China announced on March 31 that the virus had been discovered in humans for the first time and had confirmed 21 deaths and 104 cases by Monday with another fatality in Shanghai and two new cases in neighbouring Zhejiang province.

A World Health Organisation official reiterated Monday there is still no evidence that a new strain of deadly bird flu is passing in a "sustained" fashion from person to person, despite fears some family members may have infected one another. "Right now we do not see evidence of sustained human-to-human transmission", Keiji Fukuda, the WHO's assistant director-general for health security and environment, said at a press conference. He added, however, that officials "are always worried whether there could be person-to-person transmission".

The death toll from a new strain of bird flu in China has reached 18, with dozens infected, state-run media reported, after experts said there is no evidence so far of human-to-human transmission. A 69-year-old man surnamed Xu is the most recent person to die from from the H7N9 virus, China's official news-agency Xinhua said on its website Saturday. He died on Friday in eastern province of Zhejiang, the agency said.