(AP)
Updated: 2006-01-10 16:22

Up to 77 people in Japan _ most of them chicken farm workers _ may have been infected with a mild form of bird flu, a news report said Tuesday, citing government officials.

The sufferers came from two prefectures _ Saitama and Ibaraki _ outside of Tokyo, Kyodo News agency reported. Officials at the Health Ministry refused to immediately confirm the report.

Kyodo said the 77 showed evidence of antibodies to the H5N2 virus, which is weaker than the deadly H5N1 form. None of them showed signs of the disease and there was no danger that they would, the report said.

The H5N1 virus has killed at least 76 people worldwide since 2003, according to the World Health Organization's Web page.

Japan so far has suffered one case of human infection of the more deadly virus, but no deaths.

There have been several outbreaks this year of bird flu among poultry flocks in Ibaraki, about 100 kilometers (65 miles) north of Tokyo.

Japan has culled hundreds of thousands of birds to stop the disease's spread since it was detected in the country in 2004 for the first time in decades.

Most of the human infections in the world have been linked to direct contact with sick poultry, but scientists fear that the virus could mutate into a form that spreads easily between humans, sparking a global flu pandemic that could kill millions.

There is no known cure or vaccination for H5N1 in humans.