The heath ministry said Saturday that five people who tested positive for an antibody to the bird flu virus after an outbreak of the disease hit poultry in February in Kyoto Prefecture have no possibility of developing the disease or infecting others.
The ministry is examining and assessing the test results on four former workers at Asada Nosan Co.'s Funai Farm in the town of Tamba and one employee of a livestock health center, the officials said.
They said the ministry plans to report the findings around Wednesday.
According to the ministry, a blood test was given to 16 former workers at the farm, 20 livestock health center employees and 22 employees of the Kyoto Prefectural Government. All took part in operations to dispose of chickens at the poultry farm or disinfect the farm in February and March following the outbreak.
The five may have been infected with the disease, but that has yet to be confirmed. If confirmed, the cases would mark the first human infections from avian influenza in Japan.
Some 240,000 chickens and 20 million eggs were disposed of at the farm and another nearby farm to prevent the infection from spreading.
Bird flu had earlier broken out among poultry in Yamaguchi Prefecture in January and in Oita Prefecture in February.
All of the cases have been found to be infections of the H5N1 type of virus.
The disease has spread among poultry in several Asian countries, including South Korea, Vietnam, Thailand and China.
The World Health Organization says there have been 44 cases of human infections in Thailand and Vietnam, in which 32 people have died.