Health departments across Oklahoma are warning about flu cases on the rise. Officials said flu activity across the state has ramped up significantly two weeks into the new year. Twelve Oklahomans have died and 649 have been hospitalized due to the flu since this flu season began on Sept. 1, 2019, according to officials with the Oklahoma State Department of Health.According to the health department, three of the deaths were reported in Oklahoma County, four in Tulsa County, one in east central Oklahoma, one in northeast Oklahoma, one in northwest Oklahoma and two in southeast Oklahoma.Seven of those who died were over the age of 65, four were between the ages of 50 and 64 and one was between the ages of 18 and 49.Click here to learn more.