That may not be true, and actively isn't true for other parts of the developing world. I rather vividly remember a presentation given by PAHO a couple years ag

That may not be true, and actively isn't true for other parts of the developing world. I rather vividly remember a presentation given by PAHO a couple years ago on their rubella control efforts in South America, and how frustrating it was to have outbreaks kicked off by import cases from wealthier European and North American countries.