Public health officials are investigating an influenza outbreak at a Michigan university that has resulted in more than 500 cases, as several schools have also seen surges in flu activity. The University of Michigan's Ann Arbor campus in Washtenaw County has reported over 525 cases among students since Oct. 6 -- about three-quarters of them among people unvaccinated against the flu... ...Other campuses are also battling flu outbreaks. Rowan University in Glassboro, New Jersey, has logged 150 flu cases among students since Nov. 1... Spikes in flu cases have also been seen at Florida State University and Florida A&M University,...