Influenza outbreak may spread nationwide

Japanese authorities are warning that an influenza outbreak may spread nationwide this winter.

The National Institute of Infectious Diseases says that 3,333 influenza cases were reported by about 5,000 medical institutions across Japan in the week that ended on Sunday. That's up more than 1,200 from the previous week and is the biggest increase so far this season.

The institute says 69 percent of the patients have seasonal type A influenza, and 27 percent are infected with the H1N1 strain. Japan had a major outbreak of H1N1 influenza last winter.

The institute is advising people to take precautionary measures such as washing their hands and having vaccinations.