An employee of a Japanese pharmaceutical research and development company has been found infected with herpes B virus which is commonly found among monkeys. This is the first confirmed B virus infection in Japan.
B virus infection in people is usually caused by contact with monkeys. It can lead to brain fever, disturbed consciousness, even death.
Officials in Kagoshima City, western Japan, say the patient was working at a local company involved in the research and development of drugs. The employee reportedly assisted experiments involving monkeys.
The person visited a hospital complaining of a headache and fever.
The National Institute of Infectious Diseases confirmed earlier this month that the patient contracted the B virus and is in critical condition.
There is no record of the employee being bitten by a monkey, and it remains unknown how the infection occurred.
Health ministry officials and local authorities say they have inspected the company's facilities and found no problems with its management and control measures against infectious diseases.
Human infection of the B virus is extremely rare worldwide.
The US Centers for Disease Control and Prevention says 50 people, mainly in the US, have been found infected with the virus since 1932, and 21 of them have died.
The CDC says the risk of human infection is extremely low even if they are bitten by wild monkeys, and there has been only one reported case of human to human infection.