Working in the field, I can tell you there a lot of similar incidents all across the country. For that matter, although it may depend on the case or statutory law or the regulations of a given state, there is generally no obligation for a healthcare provider to tell the employer or patients that they have an infectious disease, mental illness or the like. So your doctor could have HIV and you would likely never know about it unless he/she voluntarily told you. This is all confidential under medical privacy laws/ADA with some possible exceptions.
This is of course not limited to healthcare. It applies to Officer Joe, Firefighter Joan, Programmer Bill, Risk Manager Michael, Teacher Sam, Lawyer Janet, Secretary Fred or Plumber Ed. They don't have to tell their employer or customers, students, clients, co-workers or anybody about their medical condition, especially if they are not seeking any sort of accommodation for it.