The H1N1 swine flu tally grew to 292 on Thursday after Kyoto confirmed its first case and Tokyo confirmed its third, placing the virus in six prefectures so far.
The first cases in greater Tokyo, two high school students in Tokyo and Kawasaki, put the national and local governments on alert Wednesday for a possible epidemic in the densely populated metropolitan region, which encompasses Tokyo, Chiba, Saitama and Kanagawa prefectures. The third case, a woman in Meguro Ward, was announced Thursday night.
The new flu, locally called “shingata infuruenza” (new-type influenza), “has become substantially widespread inside the country,” Health, Labor and Welfare Minister Yoichi Masuzoe told the Diet Thursday, although the government maintains that Japan is still in the early stages of a domestic outbreak.
The 16-year-old girls, whose names are being withheld, both attend Senzoku Gakuen High School in Kawasaki.
They shared a room at a New York hotel from May 11 to 18 while participating in a mock session of the United Nations and returned to Narita airport at 1:55 p.m. Tuesday on a Continental Airlines flight, the Tokyo Metropolitan Government said.
Both were hospitalized and are recovering, officials said Thursday. They have not returned to school since returning from the U.S.
The two students tested negative for flu at the airport after developing a fever during the flight, but later reported to local health authorities and were found to have H1N1.
“This can happen when a patient is in the early stage of flu,” a Kawasaki official said.
In the Kansai region meanwhile, two new cases hit in Amagasaki, Hyogo Prefecture, along with a 10-year-old child in Kyoto, confirming infections in six prefectures.
The woman in Meguro Ward is in her 30s and returned from San Francisco on Tuesday, authorities said.
Chief Cabinet Secretary Takeo Kawamura said the government does not believe there will be an immediate swine flu epidemic in Tokyo.
Unlike Osaka and Kobe, the girls in the Tokyo area did not come down with the flu in Japan and did not infect a school, Kawamura said.
Both the Tokyo Metropolitan Government and Kanagawa Prefectural Government decided to hold off on school closures for now.
But the operator of Senzoku Gakuen High School announced Thursday it will voluntarily close the high school and other schools in the same compound until next Wednesday.
The two girls were accompanied on their New York trip by four classmates and a teacher from the school. None has shown any flu symptoms, and as a precaution they have been staying at home to avoid contact with other people. Eleven students from five other Japanese schools also went to New York for the mock U.N. session but are not showing any symptoms and have not been going out.
Kawasaki health officials said the infected girl who lives there rode a bus from the airport to Tama Plaza in Yokohama, took the Denentoshi Line to Mizonokuchi and went the rest of the way home in a taxi. She was wearing a mask on the plane and on the way home from the airport, they said.
The girl in Hachioji reportedly rode a bus from the airport and then took the Keio and JR Yokohama lines to get to her home in Hachioji.
As of Wednesday, Japan had the fourth-largest number of H1N1 patients in the world after the United States, Canada, and Mexico, where the vast majority of deaths have occurred.
Additional reporting by Masami Ito Information from Kyodo added