At the airport, if someone was exhibiting symptoms, they would immediately be separated from the rest of the people in the airport, and Public Health Agency staff would do an assessment. The next thing they would do is to send the individual to a designated emergency room for an actual assessment should that be necessary.
For individual patients, if we take another history and they have symptoms that are compatible with the illness, they will be sent to the emergency room. Paramedics or staff at the hospital emergency room will be alerted ahead of time so they can take the necessary precautions.
Once an individual has passed the international border and is in the local jurisdiction, it is the responsibility of that jurisdiction, through the very powerful local public health acts, to isolate cases and quarantine individuals. That will be done by local public health.