The USFS has asked DCV to put a warning on our brochure and we have done so. However they agree that there have been no fatal cases since 1979. I find it interesting that the secand articles hints that the reason that there have been no more recent cases could be a result of the change in the polio vacination. However, it would probably good advice not to go sniffing in the water intentionally, diving or swiming under water in the hot pools. It also appears that all places where the Ameba is found are in warm water, so I beleive that diving and swimming in the creek there is no risk. As Wizard points out this is extremey rare and it may also have to do with compromisedimmune systems. If you are intrested in reading a couple of other sources that are a little more concise I would recomend:
http://www.healthyrooms.com/amoeba.htm
http://www.reaping-rewards.com/acanthamoeba.html
Now a few questions for you hiker. Have you been to Deep Creek Hot Springs? Why is this sudenly a concern for you, do you now of any recent cases?