Lyme Disease Facts
Lyme disease is a flu-like illness caused by infection with the bacterium Borrelia burgdorferi, through the bite of an infected deer tick. The early signs and symptoms of Lyme disease include circular skin rash starting at the bite, fever, headache, and fatigue. Without treatment, infection can spread throughout the body, including the joints, spine, brain and heart.
The stages of Lyme disease are progressive and depend on treatment interventions:
Early localized—just after the infection takes hold. Symptoms begin within hours, days or weeks after the tick bite, and can include skin rash—the characteristic bull’s-eye rash (erythema migrans)—as well as flu-like symptoms and joint pain.
Early disseminated—weeks to months after the tick bite. The bacteria are spreading farther throughout the body. Because more body systems are infected, symptoms are varied and may not look related. Symptoms include eyesight problems, rash in other areas, irregular heartbeat, pain, and nerve symptoms like numbness in the arms and legs or the face.
Late disseminated stage—weeks, months and extending months after the tick bite. Left untreated, Lyme disease can lead to such chronic conditions as arthritis, migraine, widespread pain, difficulty sleeping, and trouble concentrating.
In the United States, Lyme disease is now the most common disease borne from an arthropod (insect, spider), up from sixth place in 2015.
Recent data show:
26,203 confirmed cases reported to the Centers for Disease Control and Prevention (CDC), and about 10,000 probable cases. This is a fraction of actual cases; many cases are not reported to the CDC.
300,000 estimated cases every year. This estimate is based off reported cases and data from medical claims databases of Lyme disease diagnoses.
Lyme disease reported to the CDC is concentrated in the northeast part of the country. Maine, Vermont, Pennsylvania, New Hampshire, and Rhode Island have the highest incidence of Lyme disease.
Infected ticks are found in 14 states including those above, as well as Connecticut, Delaware, Maryland, Massachusetts, Minnesota, New Jersey, New York, Virginia and Wisconsin.
Of reported cases, Lyme disease is most common in 5- to 9-year old boys. Men (peaking again at age 50) are more commonly affected than women until age 70, when confirmed cases in women slightly outnumber men.
Other bacterial infections and diseases spread by ticks include:
Southern tick-associated rash illness (STARI)—transmitted by the lone star tick, with symptoms including rash, fatigue, fever, headache and joint pain.
Rocky Mountain Spotted Fever—transmitted by the bite of a tick infected with Rickettsia bacteria, with symptoms including rash, fever and headache.
In addition, the nonspecific and variable nature of many Lyme disease symptoms can delay its diagnosis. Conditions with symptoms overlapping with those of various stages of Lyme disease include chronic fatigue syndrome, fibromyalgia, mononucleosis, meningitis, septic arthritis, cancer, and lupus, among others.
For most people with Lyme disease, treatment is successful and there is no long-term damage or complications.
Untreated Lyme disease can progress to infect multiple body systems causing significant neurologic and cardiac problems. The longer Lyme disease bacteria are in the body and the farther the infection spreads, the more difficult it is to cure and the greater the risk for complications and poor quality of life.
Symptoms that can last from weeks to months include:
Severe joint pain and swelling
Lyme carditis (heart infection)
Meningitis or encephalitis
Thinking and memory problems
After antibiotic treatment for Lyme disease, up to 10% of patients develop what doctors call post-treatment Lyme disease syndrome (PTLDS or PLDS). This condition can persist for many months. Signs and symptoms of PLDS are similar to early stage Lyme disease and include fatigue and joint and muscle aches and pains. Patients also report difficulty sleeping, memory problems, and headache.
Some people use the term chronic Lyme disease to describe a condition marked by symptoms like Lyme disease, such as fatigue, pain, memory problems, and arthritis. However, in many of these cases lab tests for Lyme disease are negative. For this reason, Lyme disease experts support no longer using the term chronic Lyme disease.
In rare cases, Lyme disease can be fatal. The most serious threat comes from Lyme disease bacteria entering heart tissue. This is Lyme carditis, which affects about 1% of people with Lyme disease. The infection can disrupt the heart’s electrical system causing heart block, which can be fatal if not recognized and treated rapidly.
People can develop Lyme disease after becoming infected with B. burgdorferi, or the more recently discovered B. mayonii. (Other species cause the disease in Europe and Asia.) The bacteria live in the gut of the deer tick (black-legged tick). When a deer tick bites the skin, it latches and feeds on blood. Bacteria from an infected tick can pass from the tick into the person’s bloodstream.
For an infected deer tick to transmit the bacteria, it typically needs to feed for more than 36 hours. The longer the tick is attached and feeding, the greater the likelihood of developing Lyme disease. Rather than larger, adult ticks, smaller nymph-stage ticks (about 2 mm in diameter) cause most cases of Lyme disease because they are more likely to bite humans and are harder to detect. Most people bitten by a tick do not develop Lyme disease.
Symptoms typically develop between 3 and 30 days, the incubation period for B. burgdorferi. There is evidence the severity of disease and symptoms depends on the person’s immune system. In other words, some people may be more at risk than others for developing Lyme disease.
It’s possible to become infected a second time and develop Lyme disease again after an initial infection and treatment for early Lyme disease.
To remove a tick, use fine-point tweezers to hold the tick as close to its entry point in the skin as possible. Pull back firmly in a controlled motion without jerking or twisting the tick. Gently wash the area and disinfect it with a cotton ball soaked in rubbing alcohol or an alcohol wipe.
The tick can be saved in a plastic bag for testing. However, the CDC does not recommend testing ticks for the disease. Just because a tick is carrying the disease-causing bacteria doesn’t mean it has been transmitted through a bite. If the tick tests negative for bacteria, it doesn’t exclude the possibility of infection from a different tick bite.
An accurate diagnosis requires a physician experienced with the signs and symptoms of Lyme disease. The doctor also considers the patient’s confirmed tick bite or probable exposure to deer ticks. The fact that symptoms associated with Lyme disease—fatigue, difficulty concentrating, flu-like symptoms, and joint pain—overlap with several other conditions can delay diagnosis.
A two-step lab test that detects antibodies to the bacteria is available to help confirm a Lyme disease diagnosis. It requires a blood sample. Both tests must be positive to confirm Lyme disease. Results are likely to be negative the first few weeks after infection because the body has not yet built up enough antibodies for the test to detect. The Lyme disease test is most accurate a few weeks after infection.
A 10- to 14-day course of antibiotics in pill form early after infection can often cure Lyme disease. Antibiotics can also be effective in the later stages of disease, but the outcome varies among individuals. Patients in later stages of Lyme disease—those with acute joint pain or showing signs the infection has spread to the heart or central nervous system (brain and spinal cord)—may require intravenous antibiotics. In addition to antibiotic treatment, doctors may prescribe medication or recommend treatment to relieve Lyme disease symptoms, such as arthritis.
Antibiotics for Lyme disease include:
Ceftriaxone (intravenous administration)
Long-term antibiotic treatment is not more effective than the normal length of antibiotic treatment. In fact, extended antibiotic therapy can carry significant health risks, including possible bloodstream infections or heart tissue damage.
The number of Lyme disease cases has been increasing the last 25 years. Improvements in prevention will help control these numbers. To prevent Lyme disease, avoid areas known to harbor infected ticks, use insect repellent, perform a body check after being outdoors, and remove ticks as soon as possible. Research is underway on a Lyme disease vaccine.