Jenny,
This is everything I know about Lyme disease and some links/etc. to get more information. I hope this helps.
Lyme disease is a bacterial illness caused by a bactrium called a spirochete. It's relationship to ALS is some of the symptoms of Lyme disease are the same as some of the symptoms of ALS.
It was named after the town it was discovered in in 1975. That being Lyme, Connecticut.
Generally, Lyme blood testing is helpful in a patient with symptoms compatible with Lyme disease who has a history of tick bite at least a month prior or unexplained disorders of the heart, joints, or nervous system that are characteristic of Lyme disease. Antibodies are produced by the body to attack the bacteria and can be evidence of exposure to the bacteria. This antibodies can be detected using a laboratory method called an Elisa assay. Currently, the confirmatory test that is most reliable is the Western Blot assay antibody test. More accurate tests are being developed.
Most Lyme disease can be
CURED with antibiotics.
ALS is not currently curable, cannot be determined by a simple blood test and does not originate from tick bites.
This is a link to the CDC's web information on Lyme disease. If you digg or google lyme disease, you'll invariably run into some good information on the Elisa array and the reason for "false" positives. The antibodies in the blood can stay there long after treatment/cure.
Whew...That rung my little noggin out like squeezing a lemon. I hope it helps.