Japan said Sunday that 13 more high school students had tested positive for swine flu, as senior health officials gathered in Geneva for talks on how to contain the spread of the virus.
Station employees wearing facemasks stand at attention next to automated ticket gates as passengers enter and leave Kobe's JR Sannomiya Station in Kobe, Hyogo prefecture, in western Japan on May 17, 2009. (AFP Photo)
The flu cases were detected in Japan's western Osaka prefecture and the city of Kobe in adjacent Hyogo prefecture, where eight students already have the virus, prompting fears that A(H1N1) influenza could be entrenched in the area.
"I don't know specifics about the cases (in Japan), but judging from confirmed cases the infection is likely to be spreading to hundreds of people," Japanese virologist Masato Tashiro told public broadcaster NHK.
"There must be a number of people who slipped through border controls (at airports) as their symptoms were quite light, passing the virus to other people before they knew it."
Tashiro was speaking from Geneva, where the World Health Organization (WHO) annual assembly will begin on Monday, with fears about the global outbreak of swine flu expected to dominate discussions.
Nearly 8,500 people in three dozen countries have been infected with A(H1N1), according to the latest figures released by the WHO. Cases confirmed in Turkey and India at the weekend have not been included in the tally.
More than 70 people have died from the virus -- all of them in the Americas and nearly all of them in Mexico, where the new strain of swine flu was first detected less than a month ago.
Acting WHO Assistant Director General Keiji Fukuda has said that studies indicate a "significant number of people" have been infected but their cases had either not yet been detected or confirmed by laboratory tests.
A motion has even been put forth to shorten the talks in Switzerland from 10 to five days, so that senior officials are not away from their duties at home for so long.
Ahead of the WHO meeting, world governments failed to reach a final deal on the sharing of virus research material and vaccines in case of a global flu pandemic.
Mexican President Felipe Calderon said his country had given the WHO a sample of the virus on Saturday, along with statistical and clinical data on the evolution of the strain there.
Authorities in Mexico say that they are on the path to controlling the outbreak. The health ministry said in a statement that if the virus "is dealt with on time, usually it is curable."
In Japan, officials shut down schools and cancelled public events in Kobe as a preventive measure.
So far no link has been found between the students in Osaka and Kobe who tested positive, officials said, adding that about 100 more teens in Osaka were to be tested, along with seven people in Hyogo prefecture.
Prime Minister Taro Aso urged the public to remain calm while Shigeru Omi, head of the government's special swine flu task force, said: "We believe that the infection is beginning to spread in the region."
Earlier this month Japan had confirmed four other cases of swine flu -- a school teacher and three students who flew to Tokyo from Canada via Detroit. Those people have since recovered.
The WHO has not yet recommended travel restrictions to curb the spread of the virus, but has advised anyone who is feeling unwell to postpone their trips.