By Martha A. Simpson, D.O., M.B.A.
Associate Professor of Family Medicine
Ohio University College of Osteopathic Medicine

LYME DISEASE CAN BE SERIOUS, CDC OFFERS PREVENTION TIPS

Question: I live in rural Ohio and am outdoors a lot in the spring and summer. How concerned should I be about Lyme disease? We have many deer in our area, and I know this increases the risk. What are my risks of getting Lyme disease?

Answer: Lyme disease is caused by a bacterium (Borrelia burgdorferi) which is fairly common in some parts of the United States. According to the Centers for Disease Control and Prevention, 23,763 people contracted Lyme disease nationwide in 2002. Ninety-five percent of these cases were in the states of Connecticut, Delaware, Rhode Island, Maine, Maryland, Massachusetts, Minnesota, New Jersey, New Hampshire, New York, Pennsylvania and Wisconsin. Ohio was listed as low risk. So in your case, your “concern level” should be relatively low.

The bacteria that causes Lyme disease must reside inside of another living creature in order to survive. The deer tick (Ixodes dammini) then spreads that bacteria from animal to animal or animal to human.

The life cycle of the tick lasts two years. The female tick lays eggs in the spring. These hatch into larvae, which feed once during the summer on the blood of mammals, usually mice. The larvae change into young ticks called "nymphs" the following spring and feed once during the summer on mice, dogs, deer, or humans. The nymphs then molt into adult ticks. In the fall, they feed on another mammal –- often white-tailed deer. If one of these feedings is on an animal infected with the bacteria that causes Lyme disease, the tick can give the infection to the next animal upon which it feeds. So the tick doesn’t cause Lyme disease, but it does spread it.

Infected humans develop a rash with a “bulls-eye” appearance. The rash clears up without treatment, only to appear in another spot. Since 50 percent of Lyme disease victims don’t recall having a tick bite, this rash is usually a crucial clue in arriving at the correct diagnosis. While the rash is present, or sometimes when it’s over, a flu-like illness develops with headache and muscle and joint aches. As the disease progresses over several weeks to months and becomes chronic, 10 to 15 percent of untreated individuals will develop serious problems in the nervous system, heart and joints.

The symptoms of chronic Lyme disease often mimic other diseases. Though lab tests can aid in the diagnosis, physicians must often establish the diagnosis by excluding other possible causes of the symptoms. This is unfortunate because the delay in treatment decreases the chance for total recovery.

The treatment of Lyme disease involves the use of antibiotics, usually taken by mouth, though in some cases, by IV. The antibiotics may be continued for four weeks or more, depending on how long the disease has been present. In cases of longstanding disease, the treatment may fail and additional antibiotic therapy may be necessary.

Lyme disease can be a very serious illness, so it’s a good idea to take steps to prevent it, especially if you live in one of the high risk states I mentioned earlier.

Here are some suggestions from the CDC: if you are going to be in areas that are tick infested, wear light-colored clothing so that ticks can be seen and removed before becoming attached. Wearing long-sleeved shirts and tucking pants into socks or boot tops may help keep ticks from reaching your skin. Ticks are usually located close to the ground, so wearing high rubber boots may provide additional protection.

The risk of tick attachment can also be reduced by applying insect repellents containing DEET (n,n-diethyl-m toluamide) to clothes and exposed skin, and applying permethrin (which kills ticks on contact) to clothes. DEET can be used safely on children and adults but should be applied carefully following the label instructions to reduce the possibility of toxicity.

Family Medicine® is a weekly column. To submit questions, write to Martha A. Simpson, D.O., M.B.A., Ohio University College of Osteopathic Medicine, P.O. Box 110, Athens, Ohio 45701, or via e-mail to readerquestions@familymedicinenews.org. Medical information in this column is provided as an educational service only. It does not replace the judgment of your personal physician, who should be relied on to diagnose and recommend treatment for any medical conditions. Past columns are available online at www.familymedicinenews.org.