BEIJING, Feb. 10 (Xinhua) -- Viral analysis of patients infected with bird flu in the Chinese mainland found no mutation that could cause human to human infection, Mao Qun'an, spokesman of the Ministry of Health, said Tuesday.

    Mao said that eight people were found to have contracted H5N1 this year and five had died. Scientists had found little mutation in the virus strains separated from those patients, and no mutation that would allow human-to-human transmission.

    Mao said the other three patients had recovered. A 3-year-old girl surnamed Peng in northwestern Shanxi Province and a 29-year-old man surnamed Zhou in southwestern Guizhou Province were released from the hospital a few days ago. Both were hospitalized last month.

    A patient in central Hunan Province surnamed Shu also recovered and will be released from the hospital soon, Mao said.

    Most patients had direct contacts with live poultry or worked at poultry markets, he added.

    Since the World Health Organization identified the lethal virus, 406 human cases from 15 countries had been reported, according to Mao.

    Mao urged health departments and hospitals to be vigilant, since most human infection cases occurred in the first quarter of the year.

    He said early diagnosis and treatment could increase the survival rate for H5N1 patients.