Famous pandemic control expert Zhong Nanshan said that bird flu is approaching human beings through three possible channels: bird flu itself, live poultry and other animals.

"An urgent task at present is to carry out nationwide publicity as quickly as possible," said Zhong, a member of China's top advisory body, National Committee of the Chinese People's Political Consultative Conference (CPPCC).

Zhong, who is in Beijing to attend the annual session of the CPPCC National Committee, said bird flu is affecting human beings.

A patient in Guangzhou who died of bird flu did not have direct contacts with dead poultry. "It's possible that live poultry may also carry bird flu virus," said Zhong.

It's possible that other animals, including cat and pig, may also be infected with bird flu, he said.

Zhong praised government work in preventing and controlling human infection of highly pathogenic bird flu, but he noted that publicity is not enough, especially in some rural areas.

"Some people there are not alert for bird flu. They don't report serious pneumonia cases to relevant departments when they hear of them," said Zhong.

On the other hand, people should not be over-worried about the spread of bird flu, Zhong said. "The majority of people are not sensitive to the current strain of bird flu."

He said China has done a fairly good job in monitoring wild poultry. In addition, some cities have began monitoring serious cases of pneumonia. The information system is being improved and research and development of vaccines have made progress.