There is a similar system in the U.K. It's called Port Health there. These are portals of entry into the U.K. It's very similar to what is here. There is somebody whose responsibility it is to pick out people who are sick when they're travelling, or who might present a security risk. They are not looking for terrorists, but perhaps people who are psychologically unstable.
They pick up people like that and either treat them or isolate them. Sometimes they actually send them back to where they came from, but it is a health role. They have health associates in the airport or at the port.