The epidemiology aside, what effect will this have on travel in the region? Recall that as a result of SARS, travel in the Pacific Rim cratered.
That depends on how decisively authorities react. I heard this morning (NPR, but details are fuzzy) that travelers arriving to (where?) from Wuhan are going to be held in 14-day quarantine.
The immigration tools, and public health tools, to clamp down on international travel are pretty broad and effective. To use just travel between China and the U.S. as an example, the U.S. is under no obligation to accept flights from China - these operate by mutual treaty. Similarly, the U.S. could set health screening protocols for travelers on flights China-USA just as it sets security screening protocols. The U.S. could, probably on less than 24 hour notice, demand that:
- all travelers from China direct to the U.S. be screened for health and recent travels
- permits flight from ONLY PEK/PVG/HKG
- to ONLY LAX/SFO/EWR/JFK (cities where medical personnel and facilities are numerous)
- where arriving travelers will receive another health screen and suspect individuals quarantined
- until the U.S. government declares differently
I'm not saying that's the way to deal with this (while human-to-human rates of transmission, lethality, and incubation period are unknown), but it's possible. It wouldn't take a new treaty. It doesn't demand new legislation.