Doctors have seen a big increase in patients with flulike symptoms at St. Mary's Convenient Care in Evansville, where physician John Honningford said there's been "a marked increase" in flu cases over the past two weeks. He estimated there have been between 30 and 40 diagnosed cases of flu at the clinic within the last month.
January and February typically are the peak flu months in the U.S., although small numbers of flu cases circulate for much of the year.
Dr. Fred Wallisch, medical director at Deaconess Clinic in Evansville, said there's still time for people to get vaccinated.
"Most of the people coming in with it have not been vaccinated," he said. "It's not 100 percent (effective), but it is beneficial."
At Reid Hospital in Richmond, Dr. Thomas Huth said the hospital has seen about 50 flu cases during the past week alone.
"It's definitely flu season in our area," Huth said in a statement.
The average age of Reid Hospital's flu patients so far is 23; the youngest was a 1-month-old and the oldest 78.
Flu symptoms often appear quickly and include a fever, cough and/or sore throat, runny nose and headaches or body aches. Unlike a stomach virus, the flu virus typically does not cause symptoms such as diarrhea and vomiting.
The best time to treat flu symptoms is 72 hours after the symptoms begin, said Randi Whitesel, registered nurse and unit manager for Reid Hospital's occupational medicine department.
"If you feel uncommonly ill with flulike symptoms and are experiencing shortness of breath or a high fever, it's time to see your primary care doctor," she said. "An urgent care center is the next-best option, and then the emergency department."