Connecticut health officials say they have seen a sharp increase in the number of influenza cases over the past month.

Doctors say they have gone from treating almost no flu cases three weeks ago to more than 300 cases a week. In Norwalk, health officials say they have seen at least five to 10 cases of the flu virus a day.

Dr. Michael Carius, chairman of Norwalk Hospital?s Emergency Department, says most of the flu patients are those who did not get vaccinated.

Carius warns that influenza can lead to more serious illnesses, such as pneumonia, especially in the elderly and the very young. He urges people who experience common flu symptoms like fever and shortness of breath to see their physicians.