it is because, in part, that those folks that travel internationally tend to be well fed, healthy, and most have appropriate healthcare. The close quarters comes into play with airborne diseases, especially on airplanes, and those folks who have not gotten vaccinated for the diseases that used to wipe out large numbers of folks. you know, when the diseases would run rampant, prior to us having access to vaccines. I am from the camp of people who are glad we hav chlorine in out water so our young children don't die from bloody diarrhea, and I am glad I will never have to see my child suffer with polio. Yes, I am aware vaccines are imperfect, and that disinfectants in our water might be causing other health ailments. I will stop there because that opens a can of worms.We do have these conditions already with international air travel for business and pleasure. Humans are extraordinarily lucky that no pathogen has fully taken advantage of how aggressively we intermingle on a global scale. Imagine if we could stay asymptomatic carriers of something for days or weeks, infecting other asymptomatic carriers along the way, only to later break out in disease which quickly kills us and everyone around us. The first worldwide human pandemic of the new millennium with real bite will be truly something to see; and I guess you're right, the CDC will definitely be involved at that point!
omg, I derailed again sorry. ;Facepalm