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You are assuming the virus will not mutate.
Not sure why it would have to mutate to make it more than sporadic in the USA. While we may have better medical care and healthier conditions than Africa, and don't eat bat meat and share plates or hug our recently deceased Ebola victims; there are numerous ways the virus is transmitted (sweaty palm on the door at the airport that can leave the Ebola there for a few days, etc.)
And it won't take much for it to overwhelm the capacity of approved, secure facilities. And how many Americans, at the first sign of symptoms will be going to get treated once they realize it will mean 21 days of quarantine before they can go back home, go to work, etc.
The quarantine is for waiting for symptoms to appear after an exposure. A person who is sick can be tested; there is a specific protocol for establishing that they have truly recovered and can leave the hospital. They should, however, avoid breastfeeding and intimate acts for several weeks afterwards.
The virus cannot mutate very rapidly, due to its physical structure. If it were to become airborne (unlikely), it would be a huge problem. It does not spread easily in its current form--as you noted, practices here in the US do not favor its spread.
Well... unless the clinic has WIFI, they probably won't go.