Our doctor told us it was OK to go on vacation, so we planned to go to southern Arizona, mostly hiking in the desert. I haven't been able to find anything about this in books or on the web. Sorry for the delay in replying to your question.
Valley fever is an illness caused by a fungus called coccidiomycosis.
It is common in places like the desert in Arizona. People who are not from these areas are at some risk during travel especially if they breath in dust and spend alot of time out in the desert. If you are driving through an endemic area it is suggested that you leave the car windows up. The risk is related to the amount of exposure to soil. If your destination is a resort in Arizona you should be fine if you stay by the pool.