Flu hits 'alarm level' in Japan for 1st time this winter

Influenza reached the "alarm level" for the first time this season after an estimated 1.73 million flu cases were reported last week, an increase of more than 50 per cent from the previous week, the health ministry said Friday.

According to the Health, Labor and Welfare Ministry, about 5,000 medical institutions throughout the country reported an average of 35.95 flu cases in the week starting Jan 23, exceeding the alarm level of 30, ministry officials said.

The average has surged from 22.73 new flu cases per institution, which was the "alert level," the previous week. It also eclipsed last year's peak of 31.88.

The number of new flu patients was estimated at about 1.73 million, up from about 1.1 million the week before.

The Type A Hong Kong flu virus accounted for about 90 per cent of these cases. As this virus has not seriously hit the country for the past four seasons, most new infections have been among children who have not built up their immunity to it.

More than 60 per cent of flu patients during the week were 14 or younger, with about 500,000 aged 5 to 9, about 330,000 aged 10 to 14, and about 260,000 aged up to 4, the ministry added.