You have many questions. At first it seemed as if you were curious about what other aspects the CDC had delved into. Now it looks like you are pursuing some agenda. The basic questions can be answered with a bit of research. Here are some more to ponder. Or maybe these are what you are getting at.
What was the CDC's original mission?
Did it execute it competently?
Why is it now involved in areas other than communicable diseases?
Do people in organizations seek to increase their power and influence?
Do they do this by enlarging the scope of their organizations' missions?
How is this notionally science-based entity being influenced by other factors?
I actually suspect this role was thrust on the CDC because they are generally supported by everyone (everyone sane anyway). I'm not a fan of this having happened because they should be too important to get mixed into politically poisonous debates.
What was the CDC's original mission?
Did it execute it competently?
Why is it now involved in areas other than communicable diseases?
Do people in organizations seek to increase their power and influence?
Do they do this by enlarging the scope of their organizations' missions?
How is this notionally science-based entity being influenced by other factors?