TOKYO, Feb 3 (Reuters) - Japan has confirmed that a bird flu outbreak at a poultry farm in a southwestern prefecture was caused by the H5N1 virus, making it the fourth such outbreak to hit the country this year. The Agriculture Ministry said in a statement on Saturday that test results had shown that the outbreak in Miyazaki prefecture, first detected earlier this week, was due to the H5N1 virus. The H5N1 bird flu has already been confirmed at two other poultry farms in Miyazaki, Japan's largest poultry-producing region, and at one farm in the western prefecture of Okayama. The H5N1 virus has killed at least 164 people worldwide since 2003, most of them in Asia, and more than 200 million birds have died from it, or have been killed to prevent its spread. There have been no reported cases of human infection from the virus in Japan. The country suffered four outbreaks of the H5N1 bird flu in 2004, but has been free of it until it emerged this year.
