One person caught the bird flu virus while working at a contaminated poultry farm after an outbreak in Japan last February, in the first case of human infection confirmed in Japan, the government said Wednesday.
The Health Ministry said blood samples taken from five Japanese earlier this year were tested for avian influenza, and one had antibodies for the disease, confirming the infection. The four others were probably infected but tests weren’t conclusive.
It was the first confirmed case of human infection from the disease in Japan, the ministry said in a statement, which did not reveal when the confirmation was made.
Bird flu swept through farms across Asia this year, forcing officials to destroy more than 100 million birds. The disease also jumped to humans, killing 12 people in Thailand and 20 in Vietnam.
Although there has been no evidence of human-to-human transmission, experts worry that the virus could mutate into a version easily spread among people, thus sparking a global pandemic.
The case confirmed here involved an employee at Asada Nosan Co.’s Funai Farm in Kyoto Prefecture, which was the center of the outbreak in February.
After a month spraying disinfectant around the farm from late February, the employee got a headache that lasted for several days but showed no other symptoms, the ministry said.
After the farm was disinfected, the prefectural government took blood samples from about 86 people, including farm employees, firefighters and local government employees who took part in the operation.
The samples were examined by the National Institute of Infections Diseases in Tokyo.
On Friday, the government said blood samples from five people tested positive for the virus. At the time, officials were unable to determine if any of them had actually contracted the disease.
It wasn’t clear how the five were exposed to the virus. But one said he hadn’t worn a mask at the farm even after the virus was discovered there, the ministry said Wednesday.
Tests showed that it was “highly possible” the other four — three farm workers and a city inspector — also had been infected, though none of them became ill, the ministry said.
In August, the Kyoto District Court handed Asada Nosan’s operator, Hideaki Asada, a one-year suspended prison sentence for covering up the outbreak and violating livestock hygiene laws.
Asada’s parents, who helped run the farm, committed suicide because of the scandal.