Authorities in South Korea said tests have confirmed that an American citizen in the country has swine flu. The Korea Centers for Disease Control and Prevention said Saturday that the 23-year-old woman, who came to the country earlier this month to work as an English language instructor, was quarantined in a hospital. It did not provide any other details. The case marks the country's fifth confirmed case of the disease. Three South Koreans have recovered and a Vietnamese will be released from a hospital in a few days, the KCDC said.