Hey, Congrats!!!
I attend Columbia as an undergrad, and I'm graduating this May. I'm really familiar with the Mailman School of Public Health, since I worked there part-time as a research assistant, and and taking a class there this semester. I am going into health education, and I found out this weekend that I got accepted into Emory, too!! I didn't apply to Mailman, though, partially because they don't offer health ed., only health promotion, and those two fields are related but not quite the same.
Anyway, in making a decision, I know undergrads here at CU also interested in global health, and I have to say, NYC is the place to be for that field. I have classmates who've been able to work at the UN headquarters downtown as undergrads, so just think of the possibilities awaiting you as a grad student. Also, I don't know if you've ever visited Mailman, but as soon as you walk in, you get a sense that the school is highly dedicated to that field (there are pictures depicting global health disparities throughout the main floor). The school is strong in every department, but I truly belive it's an amazing school for global health.
On the other hand, Rollins has the CDC partnership, which also might be good. However, in your case, you should use New York City as your stepping stone, and it's likely that Atlanta may be more appropriate for me since I'm interested more in domestic health. I mean, you can always go to Atlanta during a summer to work...Anyway, if you want to write me back through this forum, we can maybe can chat here or by phone about this. Good luck, my fellow soon-to-be MPHer!!!