An outbreak of influenza, often rampant around this time of year, could be the worst in a decade, the Health and Welfare Ministry warned Jan. 15.According to recent statistics released by the ministry, the number of people who appear to have contracted the virus in the latter half of December reached a record high when compared with the figures for the past decade. In addition, more than 68,000 elementary and junior high students had contracted the flu by the end of December, the figure being higher than that for the same time last year, according to the ministry.Anticipating that this winter will bring an even more severe outbreak than that of two years ago, when the disease affected more than 800,000 young students, the ministry urged the public to gargle and wash their hands regularly. “Children and the elderly should be particularly careful,” warned a ministry official. “Go see a doctor when you run a high fever and cannot shake off a cough.”According to the ministry’s survey, compiled from some 2,500 medical institutes nationwide, in the latter half of December each institute diagnosed an average of 19.07 flu patients a week, a record in the last decade. The number of recorded flu cases for that period was higher in the Tohoku and Hokuriku regions compared with other parts of the country, the ministry said.Of the two main strains of the influenza virus that strike Japan, the ministry said Hong Kong A is prevalent this year. The other strain is Soviet A.