Japan's health ministry has confirmed the country's first instance of a human catching the bird flu virus.
Millions of birds have been culled as a preventative measure
Officials think four other people have probably caught the disease too.
None have developed any serious symptoms, and the ministry has discounted the possibility of the infection spreading.
Bird flu has swept through Asia this year, causing the deaths of more than 30 people. Millions of chickens have been culled as a preventative measure.
According to Japan's health ministry, blood samples taken from all five cases indicated bird flu. One person's blood was found to contain antibodies to the disease, confirming he has the infection.
The man concerned was an employee at Asada Nosan Company's Funai Farm in Kyoto prefecture.
There was an outbreak of bird flu in chickens at the farm in February, and the man spent a month spraying disinfectant around the area, the
The infected employee suffered from a sore throat and a headache for a few weeks, but has since recovered.
More than 100 million birds have died or been killed around Asia this year because of the bird flu virus.
Experts have warned of the risk of a world pandemic if bird flu combines with a human flu virus, and officials throughout the region have been urged to take preventative measures.
On Friday the authorities in Vietnam said some 4,000 chickens had either died or been culled in the south of the country in a bid to halt the latest outbreak.
Separately, in South Korea, 9,000 ducks are being slaughtered because of the virus.