Ohio health officials are currently investigating hundreds of cases of Shigella infection that have cropped up in the state this year. As many as 770 cases have recently been reported in Columbus alone, the Associated Press reports. Many of the cases revolve around child care centers and other places children congregate, the Columbus health commissioner said. Shigella infections can be easily transmitted through human-to-human contact. According to U.S. Centers for Disease Control and Prevention tallies, Ohio has had 1,337 reported cases of Shigella illness in 2012. That’s up from 278 cases in all of last year. This year, the state with the next highest case count is Illinois with 211. Officials cannot yet explain the spike of cases in Ohio, but they are strongly advising increased hand-washing among children and caregivers. Parents are also advised to keep sick children home from school or day-care.