Danger from Deer Ticks? We live in a wooded area in central Wisconsin and often have deer in our backyard. What is a safe way to protect our two-year-old son and ourselves from ticks? Are products like Deep Woods Off safe for small children? He already has had two ticks on him this year. (I don't think they were deer ticks, as they were pretty large.) Any info on ticks and Lyme disease would be appreciated. Lyme disease is an infectious disease caused by an organism called Borrelia burgdorferi, a member of the spiral-shaped Spirochaetales order of bacteria. It's named after Old Lyme, Conn., where doctors discovered the disease when they thought they had an epidemic of juvenile rheumatoid arthritis. There were about 16,500 cases of it reported to the Centers for Disease Control in the United States in 1996. The disease presents a curious situation. There's a tremendous fascination with it as an exotic illness. And people are fearful of it because there can be persistent symptoms of it years after infection, even after treatment. So there's a tendency to rush in to this diagnosis whenever patients have strange, persistent symptoms. At the same time, a definitive diagnosis is often missed. Some physicians don't think to look for it and thus fail to give the proper treatment. To further complicate matters, there are very high false positive rates with the urine test for Lyme disease. Blood tests are much more definitive, although now there appears to be a new species of the Lyme disease spirochete that eludes the blood tests entirely. Lyme disease is usually treated with up to one month of antibiotics. If these are administered at the right time and over the right period of time, they should eradicate the organism. If the disease is left untreated, about two thirds of people develop recurring bouts of arthritis years after the infection. The disease also has been associated with neurological symptoms, although it's not clear how severe they may be. As you say, deer ticks host the organism. Deer, deer mice, and field mice carry the ticks -- which are so small, they're practically invisible until fully engorged with blood, and even then they are still hard to see. So the ticks you saw were not deer ticks. You should find out whether deer ticks are present in your area, and whether they carry the bacteria that causes Lyme disease. Ticks may carry 10 major human diseases, including not only Lyme disease but also Colorado tick fever and tick paralysis. I don't recommend any chemical pesticides. The only safe insecticide is pyrethrum, which is made from a flower of the daisy family. In areas where the disease is really prevalent, like Long Island and Connecticut, the best prevention is to wear protective clothing when you go out into the woods. Wear light colors and long sleeves, and tuck your pants into your socks. When you get back, wash immediately and keep an eye out for anything unusual on your body. If you do have any odd symptoms, such as strange skin rashes, fever or joint pain, go to a doctor who is knowledgeable about diagnosing and treating Lyme disease. The typical presentation is a rash in concentric rings, like a bull's-eye. But in many cases it does not take that form. 7/4/00 Editor's Note: In December 1998, the Food and Drug Administration (FDA) licensed Lymerix, the first vaccine for prevention of Lyme disease. For more information on the vaccine, click here.