And decon the van. Again, most drivers are not trained to do this.
That is a fancy way to say "keep the thing clean."
I think you are putting more thought into this than it requires.
In your original post you mentioned HIV and Hep C patients. There are people walking around in the general populous all the time. They don't need isolation or an ambulance.
If they have active TB or some other condition requiring droplet precautions, they should be in a mask. What stops them from taking a taxi instead of an ambulance?
If you are looking for a sterile environment, most people have more than 86 different organisms as normal body flora. We do not live in a sterile environment and in fact you wouldn't be able to survive if you did.
If you do a little bit of self research you will find that "reasonable" precautions do not mean total isolation in all but the most serious of diseases.
Yea, if the guy had ebola, maybe ambulance transport would be indicated.
Also consider your company may be erring on the side of caution. It is a criminal offense to bill medicare/medicade for BLS transport fo those who not needing it. Considering the difference in revenue, I would bet your company looked into this.