The illnesses include respiratory virus, adenovirus, parainfluenza, bronchiolitis and strep throat. The symptoms include fevers of 100 degrees or higher, coughs, sneezing, wheezing and sore throat.
Dr. Paul Dungan, director of the Oklahoma City-County Health Department, said he's urging people to get flu shots.
Most at risk are young children and senior citizens with chronic heart and lung difficulties.
Dungan also urges those who have symptoms, including fever, to stay home from work or school.