H1N1 update

May 17 (Bloomberg) -- Swine flu sickened 21 more students in Japan and Turkey reported its first case of the potentially pandemic virus that’s spread to about 40 countries.

Nine high school students in Osaka, western Japan, tested positive for swine flu and another 12 are infected in nearby Kobe city, including the country’s first reported case of local transmission, Haruki Ogawa, a health ministry spokesman, said by phone from Tokyo today. A U.S. citizen who arrived in Istanbul was found to have the virus, Turkish officials said yesterday.

Health officials are trying to gauge whether swine flu, known as H1N1, is spreading in people not linked with international travel in communities outside North America, where most of the almost 8,500 cases worldwide have occurred. Evidence of that would prompt the World Health Organization to declare the first influenza pandemic since 1968.

The health ministry is investigating the route of infection for the Japanese high school students, of whom 11 are male, Ogawa said. The infected students in Osaka attend the same school, the spokesman said. Seven of the 12 in Kobe are from one school, and the ministry is checking on the others, he said.