They say Lyme is caused by the bite of ticks infected with B. burgdorferi bacteria, and that's true. But lots of other commonly known "facts" about the nation's most common bug-borne viral disease are anything but - and that's leading many people to seek costly and inappropriate treatment. Keep clicking as Dr. Orly Avitzur, medical advisor at Consumer Reports, separates Lyme disease fact from fiction...
FACT OR FICTION? You can catch Lyme from pets
FICTION. You can't catch Lyme from a dog or cat or any other animal - except a tick. Of course, pets can increase your risk for Lyme by bringing ticks into your house. What's more, it's possible to contract Lyme while removing a tick from your pet. It's important to wear latex gloves and use tweezers instead of your unprotected fingers.
FACT OR FICTION? The only way to avoid Lyme is to avoid tick bites
FACT. If you're not around ticks, you're not at risk. If you do spend time in tick-infested areas, what can you do to limit you risk? Stay out of high grass and vegetation - and as far as possible from the deer that carry Lyme-infected ticks. If you must venture into iffy places, wearing light-colored clothing will make it easier to find ticks and remove them before they attach. Be sure to wear a long-sleeved shirt and long pants tucked into your socks. Before venturing out, spray your clothes with insect repellent containing DEET. When you return inside, wash your clothes as soon as possible. Check your body for ticks, paying close attention to skin folds and hairy areas.
FACT OR FICTION? Almost all cases involve a "bull's-eye" rash
FACT. Approximately 70 to 80 percent of Lyme cases involve the telltale rash, which doctors call erythema migrans. It's characterized by a red ring surrounding normal-looking skin. The rash varies in size, shape, and color. Sometimes it itches or burns, but not always. It typically appears at or near the site of the tick bite one or two weeks after the tick bite. Since the rash often arises in out-of-the-way places like the armpits, groin, or behind the knee, it's important to examine all of your skin as closely as possible.
FACT OR FICTION? Lyme disease can cause facial paralysis
FACT. Five to 10 percent of people with untreated Lyme disease develop a one-sided facial paralysis known as Bell's palsy. Anyone who develops Bell's palsy and who lives in an area where Lyme is endemic should be tested for Lyme.
FACT OR FICTION? The blood test for Lyme is unreliable
FICTION. The CDC recommends a two-step testing regimen for patients with possible symptoms; results are considered positive for Lyme only if both parts come back positive. But the test may not detect Lyme in patients within three to six weeks of infection, before the body has had a chance to produce antibodies to Lyme bacteria. That's the word from Dr. John J. Halperin, a professor of neurology and medicine at Mount Sinai School of Medicine in New York City and the author of the forthcoming "Lyme Disease: An Evidence-based Approach."
FACT OR FICTION? Testing positive while taking an antibiotic means treatment isn't working
FICTION. The blood test for Lyme indicates not whether Lyme bacteria are present in your body but whether your blood contains antibodies to Lyme. So if you're tested during or even after successful treatment for Lyme, you may test positive. What of the claim that testing positive after treatment means treatment has failed? "Not only is there no evidence - or even theoretical rationale - to support this claim, there is no precedent for this with reference to any other infectious disease," Dr. Halperin says.
FACT OR FICTION? Fatigue and mental "slowness" mean Lyme has invaded the brain
FICTION. Some Lyme patients do develop fatigue and have trouble thinking straight. But in most cases this is the result of "toxic-metabolic encephalopathy," a transient condition that occurs with many infectious illnesses. True brain infection with Lyme - a condition called encephalomyelitis - is exceedingly rare and easily treated with antibiotics.
FACT OR FICTION? Lyme disease often proves deadly
FICTION. Though Lyme "advocacy groups" often cite cases in which people with Lyme disease have died, Halperin says there is almost no evidence to suggest that Lyme is the culprit. "One of the curious aspects of B. burgdorferi infection is how relatively benign it actually is," he says. "In contrast to many other bacterial infections, patients rarely require intensive care or even hospitalization." When Lyme seems to lead to death, odds are it's not the disease but inappropriate treatment that is to blame, he says.
FACT OR FICTION? Lyme can be sexually transmitted
FICTION. Catch Lyme from a sex partner? Fugeddaboudit. "There is no epidemiological evidence or biological foundation for this allegation, yet I've seen a number of patients who believe that they have contracted Lyme disease from a sexual encounter," says Dr. Gary P. Wormser, lead author of Lyme guidelines published by the Infectious Diseases Society of America.
FACT OR FICTION? Prolonged treatment for Lyme is best
FICTION. The notion that an extended course of treatment for Lyme works better than a short course of treatment is false. Numerous studies have shown that even in rare cases in which Lyme bacteria have invaded the central nervous system, a short course of conventional antibiotics does the trick. There's no solid evidence that treatment lasting more than four weeks has any benefit, Halperin says. And long-term use of antibiotics - especially when given intravenously rather than by mouth - can lead to deadly serious drug reactions, severe diarrhea, and potentially deadly blood infections.
FACT OR FICTION? Lyme is on the decline in the U.S.
FICTION. Cases of Lyme have tripled since 1992. In 2009, there were nearly 30,000 confirmed cases. Most were in the Northeast and upper Midwest.