According to the CDC, in most US states, breaking a quarantine order is a criminal misdemeanor. If someone broke a quarantine order, what would be done? Since the person is still contagious, would they still be incarcerated immediately?
Since the person is still contagious, would they still be incarcerated immediately?
First of all, the law takes time to operate. While there is a constitutional right to a speedy trial, nobody is ever incarcerated as a judicial punishment or penalty "immediately". The police has a time-limited right to detain persons until they can be brought to court, and then the court system approves further detainment if necessary.
There are no real rules as to where and how detainment takes place, except that the conditions must be humane. In practice, if a patient who broke a quarantine order was a real menace, they would probably find themselves chained to a hospital bed in relatively short order. The trial would probably be postponed until the person sufficiently recovers from the illness that they can aid their legal defense. If the state won on the charges in trial, the person would then be incarcerated.
Prisoners get sick too, and it is common for them to be transferred to partnering hospitals that have special wards for patients in custody - which means additional perimeter security and typically chains on the hospital beds.