I would bet the US is sending an Army Combat Surgical Hospital (CSH*) or other service equivalent, plus, since this is the US military, a bunch of dudes to guard the perimeter, feed and command and control the lot. That would be around 3,000. This number of soldiers/Marine/airmen/sailors would not be enough to do much beyond that.
* A CSH has, I think, 248 beds, and is designed to deal with trauma. This one I would guess, would be similar in size, but would be tailored in its capabilities and personnel to deal with infectious diseases. In any event, I would wager these folks will be a nervous lot. I certainly would be.