From a writer who is also an RN:
With the summer heat and humidity along with all that water floating full of dead bodies of all sorts, the CDC is gonna have to act quick to contain diseases such as typhoid, West Nile, etc. But am not sure they have the equipment and/or funding to do all that needs doing. They run on a pretty tight budget and I don't know if they can access FEMA help or not in an emergency of this scale.
The Red Cross is sending record numbers of volunteers into Alabama and Mississippi right now, staging to serve meals and provide shelter but other RC volunteers as well as Louisiana National Guard (2/3 of the state's guards, 1/3 are in Iraq) will be wading in as soon as tomorrow ito start hooking floaters and getting them into temporary morgues. The water will be contaminated enough just with dead animals (4-legged).
If they can recover all the human bodies, it'll go far to contain the contamination and disease. What will be interesting is to see how much the present admin promises and how much it delivers (often not the same figure). Florida is the only state that seems to get all the help it needs, thanks to the family connections.
Horrible situation for the folks down there.