At work in the Sierra, my daughter reports that a co-worker got "recurrent" or "recurring" fever, from the bite of a "soft tick" infected through a rat vector. The girl was hospitalized for a week, and is only one case out of seven diagnosed in the last 10 years (!) in Northern California. The cabin in which she lived is being taken apart to look for a rat infestation. I have never heard of any of this, and am concerned for my daughter. What is going on?