E.,
I think you should have your doctor fax a note to your husband's place of business. I'd say the doctor would not want to have them to come in to risk spreading more exposure to other patients. (I don't think many are actually testing for it any longer.) Also, telling the doctor this gives you more ammunition (so to speak) if the boss does try to fire your husband.
Does this person what more people out of their place of business? This could be a lawsuit waiting to happen in my opinion, but I would say Human Resources (HR Dept) is your answer. FMLA is more geared towards other medical issues. Most people are getting over H1N1 in a few days with adequate rest, fluids and proper care. As someone that previously worked in the HR field, I am not sure the boss can do this if your husband can produce a note to excuse him. If he does have the note and the doctor backs him and the boss does this, not only will he end up with a place full of others ill; but the rest of the workers could have grounds for HR legal action if they are threatened in the same manner.
It sounds like this 'boss' has some major issues (or has an issue with your husband?). If it were me, I would have the doctor send the note explaining the entire situation and concern that the boss wants to have your husband coming in to his direct boss - that person's boss and the HR department.
I'd even threaten for FOX 2 News or something of the sort to cover the story. (Bet they'd love to get their hands on that!)
Stay calm and contact the doctor's office again. Good luck and get better fast!
My hubby suggested having yours make sure to let everyone know he may be infected with H1N1 and it was come in or be fired... Of course - I think he was flabbergasted when I shared this to get input.
I feel he should let his co-workers know, especially if they have small children as not many people are comfortable with the vaccine. (I am not vaccinating myself or my son.)