There is no clear evidence in China indicating the H5N1 human bird flu virus has mutated into a pandemic strain, according to the Ministry of Health on Friday.

"We noticed that media at home and abroad paid great attention to the human bird flu case in Nanjing last December when a father and son caught the H5N1 virus," said Mao Qun'an, the health ministry spokesman, at a monthly press conference.

"So far no evidence has been found in China to support the idea that the H5N1 virus can easily pass from one person to another."

The December case took place in Nanjing, capital of eastern Jiangsu. The son, 24, the first to be infected, died on December 2. His father was later confirmed to be infected with the H5N1 virus, but recovered.

The ministry had already confirmed the father, surnamed Lu, contracted the virus through close contact with his ill son.

"Samples of the H5N1 virus taken from the father and son were almost genetically identical," Mao said, but noted there was no substantial difference.

The World Health Organization (WHO) previously warned the virus that caused the illness -- if given sufficient opportunity -- would mutate into a form that was highly infectious and easily transmissible from person to person. Such a change could start a global outbreak.

Mao said the prevention and control of bird flu had been listed as a priority of the country's public health work.

Health authorities had further improved relevant contingency plans, strengthened a national monitoring and early warning system, started vaccine examining procedures and enhanced training of grassroots health workers to boost awareness of the disease, he said.

"Health and agricultural departments will boost cooperation to strengthen bird flu prevention, and China will cooperate with international organizations in information and technology of the field."

Mao added a health news release mechanism in line with the country's regulation on transparent government, effective on May 1, had currently been set up in health departments of 31 provincial-level governments.

Local health department spokespersons will promptly release information of public health incidents and inform the public of health policies and the progress of local health work.

(Xinhua News Agency April 12, 2008)