Why are some people dying in Mexico, instead? Simple, they are drinking Mexican water. And dying of dysentry as usual.
Reports coming out of Mexico indicate something quite different. Doctors and health workers in hospitals are dying of this bug.
Not all of Mexico is a third world backwater. Mexico City is bigger than Los Angeles, and just as modern, and most of the deaths so far have happened there.
Obviously, there's something different about American immune systems and Mexican immune systems. People are dying of this virus there, while they're recovering from it here. Until a full scientific study has been done on it, no one knows why.