Can I sue my employer for violating my privacy and harassment?

My boss read a message on my personal cell phone when I was away from my desk regarding me having been diagnosed with a communicable disease. I work in a Head Start office so I am around children although I don't come in direct contact with them. Anyway, the supervisor who read the text told my other supervisors. I got called to a meeting with them and I was asked if I had this illness. I told them according to a doctor I was told I did but I was following the orders of my provider and had scheduled an appointment. It turns out I was misdiagnosed, but I am still being reprimanded with a corrective action because I did not report it to them when I thought I had it. We do not receive any training on reporting communicable diseases so this is the first I heard about having to report communicable diseases to my employer. Do I have a case here?