The number of cases of domestic new flu infections in Japan hit 42 on Sunday after a total of 34 high school and college students as well as their family members and teachers in Osaka and Hyogo prefectures were confirmed to have been infected with the new strain of influenza A.

The confirmations followed the discovery Saturday of Japan’s first eight domestic infections of new flu in Hyogo, which adjoins Osaka. A World Health Organization expert said community-level transmission may have begun in Japan, which could lead the WHO to raise its new flu pandemic alert to the highest level of 6 from the current 5.

In response to the latest development, Chief Cabinet Secretary Takeo Kawamura told reporters, ”We need to be fully prepared to prevent the further spread of infections.”

Of the 34 newly confirmed infections, 11 were detected in Osaka and 23 in Hyogo.


A total of 143 Okura high school students had been absent from the school this month due to flu-like symptoms such as fever. The privately run school said it will be closed from Monday through Saturday.

Many newly confirmed cases in Hyogo were linked to Kobe High School and Hyogo High School run by the prefecture. Experts suspect group infections at the schools in Osaka and Hyogo.

On Saturday, the government shifted its new flu action program from ”a period of overseas outbreak” to ”an early period of domestic outbreak” and called for companies and schools in the areas concerned to allow individuals to avoid commuting during rush hours.

Commenting on the discovery of the first domestic infections in Japan, Masato Tashiro, chief of the National Institute of Infectious Diseases’ influenza virus research laboratory, said that several hundred people in Japan may already be infected with the H1N1 strain of influenza A.

Tashiro, a member of a WHO emergency committee, told reporters at the organization’s headquarters in Geneva on Saturday that it is still unknown how the new flu virus entered Japan and that the infections in the country could amount to sustained human-to-human transmission in communities.

The WHO upgraded its flu pandemic alert level to phase 4 on April 27 and phase 5 on April 29, following the confirmation of widespread infections and deaths in North America. The highest stage of phase 6 refers to community-level outbreaks in two different WHO regions.