Summer is here again — and so is tick season. For those heading out into the countryside or spending their days is grassy fields, summer fun comes with summer fears of encountering these disease-carrying insects — especially in the northeastern United States. Before you head outdoors, it’s important to know what’s true and what’s not about these concerning creatures and the dangerous illness many carry — Lyme disease.
Lyme disease is the most common tickborne disease in the United States and Europe. It is caused by the Borrelia burgdorferi bacterium and on rare occasions by Borrelia mayonii. Lyme disease is carried by the blacklegged tick, also called the deer tick. The condition is named after the town in Connecticut in which it was discovered.
As with most medical conditions, prevention is key for minimizing occurrences of the disease. Prevention consists of:
- Knowing where to expect ticks.
- Treating your clothing and gear with products containing 0.5 percent permethrin. You can also buy permethrin-treated clothing and gear.
- Using Environmental Protection Agency (EPA)-registered insect repellents.
- Avoiding wooded areas with high grass and leaf litter. Walk in the center of trails.
Now, let’s take a look at some of the common beliefs about Lyme disease and the bugs carrying it — to see which is fact and which is fiction.
1. The Lyme disease bacterium is infectious to humans only during the first 24 hours after the tick bite.
Fiction. Usually, a tick must be attached for 36 to 48 hours or more before the Lyme disease bacterium is transmitted. If you remove a tick within 24 hours of the bite, it markedly decreases your chance of getting Lyme disease.
2. When you get a tick bite, get professional care for tick removal and antibiotics to prevent development of Lyme disease.
Fiction. Remove a tick as soon as possible. Professional care is not needed for removal. Antibiotics are not used before signs and symptoms are present.*
- Use clean tweezers to hold the tick as close to the skin as possible.
- Pull upward with steady, even pressure. Don’t twist or jerk it; this can cause the mouth parts to break off and stay in the skin. If this happens, remove the mouth parts with tweezers. If the mouth parts are too difficult to remove easily leave the parts and let the skin heal.
- After the tick has been removed, clean the skin and your hands thoroughly with soap and water or rubbing alcohol.
*In areas that are highly endemic for Lyme disease, a single prophylactic dose of doxycycline (200 mg for adults or 4.4 mg/kg for children of any age weighing less than 45 kg) may be used to reduce the risk of acquiring Lyme disease after a high-risk tick bite. Strict conditions must be met to be eligible for single dose prevention.
3. Signs and symptoms of Lyme disease start 3 to 30 days after a tick bite.
Fact. The following are early signs of Lyme disease:
- Muscle and joint aches
- Swollen lymph nodes, which may occur in the absence of a rash
- Erythema migrans (EM) rash:
This rash occurs in about 70 to 80 percent of cases. It begins at the site of the bite after three to 30 days (7 days on average). The rash expands over several days, up to about 12 inches in diameter. It may feel warm to touch, but it is not painful or itchy. Sometimes, it clears to form a target or “bull’s-eye” appearance.
4. Later signs may include loss of muscle tone and drooping of one or both sides of the face.
Fact. Later signs and symptoms include:
- Severe headaches and neck stiffness
- EM rashes on areas of the body other than the site of the bite
- Loss of muscle tone or droop on one or both sides of the face (facial palsy)
- Arthritis with severe joint pain and swelling, especially the knees
- Intermittent pain in tendons, muscles, joints, and bones
- Palpitations (irregular heartbeat)
- Shortness of breath
- Inflammation of the brain and spinal cord
- Shooting pains, tingling, or numbness in the hands or feet
5. Blood tests may be negative early in the course of the disease.
Fact. Laboratory blood tests are for antibodies which form in response to infection. It may take weeks for antibodies to form, so early tests may be negative. Once formed, the antibodies are present for months to years. Some other tickborne diseases, as well as some viral, bacterial, and auto-immune diseases can cause a false-positive test for Lyme disease. Newer, more reliable tests are in development.
6. Diagnosis must include the likelihood that the patient has been exposed to infected deer ticks.
Fiction. Currently, there is no certain laboratory test for Lyme disease, so the diagnosis is based on four factors, not all of which may be present. The skill and experience of the healthcare provider can be a significant factor in correct diagnosis. Consideration is given to:
- Signs and symptoms of Lyme disease
- Likelihood of exposure to infected blacklegged ticks
- Likelihood of other possible exposures or diagnoses
- Laboratory testing
7. Treatment of the erythema migrans rash consists of watchful waiting for additional signs and symptoms.
Fiction. When Lyme disease is identified as a probable diagnosis, treatment with antibiotics should begin immediately. With early diagnosis and treatment, most people will recover quickly and completely.
8. Lyme disease can cause life-threatening heart disease.
Fact. Lyme carditis occurs when Lyme disease bacteria invade the heart. It can interfere with the normal pattern of electrical signals moving from the heart’s upper to lower chambers, a process that coordinates the beating of the heart. The condition is called “heart block.” It can vary in degree and change rapidly within one person. Lyme carditis occurs in one in every 100 Lyme disease cases reported to CDC.
The symptoms of Lyme carditis include light-headedness, fainting, palpitations, feeling short of breath, or chest pain. Usually, patients also have symptoms typical of Lyme disease, such as fever, body aches, or the EM rash.
Lyme carditis is treated with oral or intravenous (IV) antibiotics, depending on severity. Some patients need a temporary pacemaker. Recovery usually occurs within one to six weeks, although Lyme carditis can be fatal.
9. When symptoms persist for more than 3 months the person receives the diagnosis of Post-Treatment Lyme Disease Syndrome.
Fiction: Most cases of Lyme disease can be cured with two to four weeks of oral antibiotics. Some patients, however, have symptoms of pain, fatigue, or difficulty thinking that last for more than six months after completing treatment. This condition is called Post-Treatment Lyme Disease Syndrome (PTLDS).
Some experts believe that B. burgdorferi can cause an “auto-immune” response with symptoms after the bacteria are gone. Other experts suggest that PTLDS results from a persistent but difficult to detect infection. Some believe that the symptoms of PTLDS are due to other causes unrelated to the B. burgdorferi bacterial infection.
There is no proven treatment for PTLDS. Patients usually get better, but it can take months to years to feel completely well. If you have been treated for Lyme disease and still feel unwell, see your healthcare provider.
10. Lyme disease can be transmitted through sexual contact.
Fiction. There is no credible evidence that Lyme disease can be transmitted sexually. The infection, however, can occur in multiple occupants in a household. Since ticks are small and easily overlooked, multiple occupants may have tick bites of which they are not aware.
11. You can get Lyme disease anywhere in the United States.
Fiction. The blacklegged ticks are native to particular geographic regions in the U.S. Those areas are where most infections occur.
- Northeast and mid-Atlantic, from northeastern Virginia to Maine
- North central states, mostly in Wisconsin and Minnesota
- West Coast, particularly northern California