Quite right .. Untreated Borrellia (Lyme's Disease) can actually be very severe (cardiac, large joint and cns involvement). You should always has some kind of pest-repellent on yourself in case you plan to camp.

Good thing you son had very TYPICAL presentation and history - H/o Hike in the woods , followed by rash with central clearing (bull's eye).

Lyme's disease is Endemic in the NE USA and some part of central US as well.

The article is a little sensationalist like I mentioned in another comment. Many parts of US (and the world) have their own set of Endemic Diseases to the Geo-location.

ps: It's untreated Borrellia infection that leas to lyme's disease.