The spiral-shaped bacterium was named for its discoverer, Willy Burgdorfer. The effects of this disease can be long-term and disabling, unless it is recognized and treated properly with antibiotics.
Lyme disease is a vector-borne disease, which means it is delivered from one host to another. It is also classified as a zoonosis, which means that it is a disease of animals that can be transmitted to humans under natural conditions.
In this case, a tick bearing the Bb organism literally inserts it into a host’s bloodstream when it bites the host to feed on its blood. It is important, however, to note that neither Bb nor Lyme disease can be transmitted directly from one person to another.
In the United States, Lyme disease accounts for more than 90% of all reported vector-borne illnesses. It is a significant public health problem and continues to be diagnosed in increasing numbers.
The Centers for Disease Control and Prevention (CDC) attributes this increase to the growing size of the deer herd and the geographical spread of infected ticks rather than to improved diagnosis.
In addition, some epidemiologists believe that the actual incidence of Lyme disease in the United States may be 5–10 times greater than that reported by the CDC. The reasons for this difference include the narrowness of the CDC’s case definition as well as frequent misdiagnoses of the disease.
Controversy clouds the true incidence of Lyme disease because no test is definitively diagnostic for the disease, and many of its symptoms mimic those of so many other diseases.
Cases of Lyme disease have been reported in 49 of the 50 states; however, 92% of the 17,730 cases reported to the CDC in 2000 were from only nine states (Connecticut, Rhode Island, New York, Pennsylvania, Delaware, New Jersey, Maryland, Massachusetts, and Wisconsin).
Japan, and China; in addition, it is possible that it has spread to Australia.
The risk for acquiring Lyme disease varies, depending on what stage in its life cycle a tick has reached. A tick passes through three stages of development—larva, nymph, and adult—each of which is dependent on a live host for food.
In the United States, Bb is borne by ticks of several species in the genus Ixodes, which usually feed on the white-footed mouse and deer (and are often called deer ticks).
In the summer, the larval ticks hatch from eggs laid in the ground and feed by attaching them-selves to small animals and birds. At this stage they are not a problem for humans. It is the next stage—the nymph—that causes most cases of Lyme disease.
Nymphs are very active from spring through early summer, at the height of outdoor activity for most people. Because they are still quite small (less than 2 mm in length), they are difficult to spot, giving them ample opportunity to transmit Bb while feeding.
Although far more adult ticks than nymphs carry Bb, the adult ticks are much larger, more easily noticed, and more likely to be removed before the 24 hours or more of continuous feeding needed to transmit Bb.
Causes and symptoms
Lyme disease is a collection of effects caused by Bb. Once Bb gains entry to the body through a tick bite, it can move through the bloodstream quickly.
Only 12 hours after entering the bloodstream, Bb can be found in cerebrospinal fluid (which means it can affect the nervous system). Treating Lyme disease early and thoroughly is important because Bb can hide for long periods within the body in a clinically latent state.
That ability explains why symptoms can recur in cycles and can flare up after months or years, even over decades. It is important to note, however, that not everyone exposed to Bb develops the disease.
Lyme disease is usually described in terms of length of infection (time since the person was bitten by a tick infected with Bb) and whether Bb is localized or disseminated (spread through the body by fluids and cells carrying Bb).
Furthermore, when and how symptoms of Lyme disease appear can vary widely from patient to patient. People who experience recurrent bouts of symptoms over time are said to have chronic Lyme disease.
Early localized Lyme disease
The most recognizable indicator of Lyme disease is a rash around the site of the tick bite. Often, the tick exposure has not been recognized. The area of rash eruption might be warm or itch.
The rash—erythema migrans (EM)—generally develops within 3–30 days and usually begins as a round, red patch that expands. Clearing may take place from the center out, leaving a bull’s-eye effect; in some cases, the center gets redder instead of clearing.
The rash may look like a bruise on individuals with dark skin. Of those who develop Lyme disease, about 50% notice the rash; about 50% notice flu-like symptoms, including fatigue, headache, chills and fever, muscle and joint pain, and lymph node swelling.
However, a rash at the site can also be an allergic reaction to the tick saliva rather than an indicator of Lyme disease, particularly if the rash appears in less than 3 days and disappears only days later.
Late disseminated disease and chronic Lyme disease
Weeks, months, or even years after an untreated tick bite, symptoms can appear in several forms, including:
- fatigue, forgetfulness, confusion, mood swings, irritability, numbness
- neurologic problems, such as pain (unexplained and not triggered by an injury), Bell’s palsy (facial paralysis, usually one-sided but may be on both sides), and a mimicking of the inflammation of brain membranes known as meningitis; (fever, severe headache, stiff neck)
- arthritis (short episodes of pain and swelling in joints) and other musculoskeletal complaints
Less common effects of Lyme disease are heart abnormalities (such as irregular rhythm or cardiac block) and eye abnormalities (such as swelling of the cornea, tissue, or eye muscles and nerves).
A clear diagnosis of Lyme disease can be difficult, and relies on information the patient provides and the doctor’s clinical judgment, particularly through elimination of other possible causes of the symptoms.
Lyme disease may mimic other conditions, including chronic fatigue syndrome (CFS), multiple sclerosis (MS), and other diseases with many symptoms involving multiple body systems.
Differential diagnosis (distinguishing Lyme disease from other diseases) is based on clinical evaluation with laboratory tests used for clarification, when necessary. A two-test approach is common to confirm the results. Because of the potential for misleading results (false-positive and false-negative), laboratory tests alone cannot establish the diagnosis.
Doctors generally know which disease-causing organisms are common in their geographic area. The most helpful piece of information is whether a tick bite or rash was noticed and whether it happened locally or while traveling.
Doctors may not consider Lyme disease if it is rare locally, but will take it into account if a patient mentions vacationing in an area where the disease is commonly found.
While antibiotics are essential in treating Lyme disease, many alternative therapies may minimize symptoms, improve the immune response, and help treat late disseminated or chronic disease. General nutritional guidelines include drinking plenty of fluids and eating cooked whole grains and fresh vegetables.
The intake of sugar, fat, refined carbohydrates, and dairy products should be reduced. Alternative therapies used in treating Lyme disease include:
- Chinese medicine. Formulae used to treat systemic bacterial infections include Wu Wei Xiao Du Yin (Five-Ingredient Decoction to Eliminate Toxin),Yin Hua Jie Du Tang (Honeysuckle Decoction to Relieve Toxicity), and Huang Lian Jie Du Tang ( Coptis Decoction to Relieve Toxicity). Inflammation at the site of infection may be treated externally with Yu Lu San (Jade Dew Extract) or Jin Huang San (Golden Yellow Powder). Specific Chinese herbs and treatments can be used for specific symptoms. For examples, for systemic bacterial infection, one may use honeysuckle flower, forsythia, isatidis, scutellaria, and phellodendron. Acupuncture and ear acupuncture treatments are also utilized.
- Herbals. Botanical remedies include echinacea (Echinacea species) to clear infection and boost the immune system, goldenseal ( Hydrastis canadensis) to clear infection and boost the immune system, garlic to clear bacterial infection, and spilanthes (Spilanthes species) for spirochete infections.
- Hydrotherapy. The joint pain associated with Lyme disease can be treated with hydrotherapy. Dull, penetrating pain may be relieved by applying a warm compress to the affected area. Sharp, intense pain may be relieved by applying an ice pack to the affected area.
- Imagery. The patient may treat Lyme disease by visualizing Bb as looking like ticks swimming in the blood-stream being killed by the flame of a candle.
- Probiotics. Probiotics refers to treatment with beneficial microbes either by ingestion or through a suppository. Probiotics can restore a healthy balance of bacteria to the body in cases where long-term antibiotic use has caused diarrhea or yeast infection. Yogurt or Lactobacillus acidophilus preparations may be ingested.
- Supplements. Use calcium and magnesium for aches, chlorophyll to aide healing, vitamin C for bacterial infection and inflammation, bioflavonoids for joint inflammation and to boost the immune system, digestive enzyme for digestive problems, vitamin B complex to boost overall health, bromelain for inflammation, and zinc to boost the immune system and promote healing.
For most patients, oral antibiotics (doxycycline or amoxicillin) are prescribed for 21 days. The doctor may have to adjust the treatment regimen or change medications based on the patient’s response. Antibiotics can kill Bb only while it is active, rather than while it is dormant.
When symptoms indicate nervous system involvement or a severe episode of Lyme disease, intravenous antibiotic (ceftriaxone) may be given for 14–30 days. Some physicians consider intravenous ceftriaxone the best therapy for any late manifestation of disease, but treatments for late Lyme disease are still controversial as of 2003.
If aggressive antibiotic therapy is given early, and the patient cooperates fully and sticks to the medication schedule, recovery should be complete. Only a small percentage of Lyme disease patients fail to respond or relapse (have recurring episodes). Most longterm effects of the disease result when diagnosis and treatment is delayed or missed.
Co-infection with other infectious organisms spread by ticks in the same areas as Bb (babesiosis and ehrlichiosis, for instance) may be responsible for treatment failures or more severe symptoms. In certain cases, Lyme disease has been responsible for deaths, but that is rare. Most fatalities reported with Lyme disease involved patients coinfected with babesiosis.
Update on vaccination
A vaccine for Lyme disease known as LYMErix was available from 1998 to 2002, when it was removed from the United States market. The decision was influenced by reports that LYMErix may be responsible for neurologic complications in vaccinated patients.
Researchers from Cornell-New York Hospital presented a paper at the annual meeting of the American Neurological Association in October 2002 that identified nine patients with neuropathies linked to vaccination with LYMErix.
In April 2003, the National Institute of Allergy and Infectious Diseases (NIAID) awarded a federal grant to researchers at Yale University School of Medicine to develop a new vaccine against Lyme disease. As of late 2003, the best prevention strategy is through minimizing risk of exposure to ticks and using personal protection precautions.
Minimizing risk of exposure
Precautions to avoid contact with ticks include moving leaves and brush away from living quarters. In highly tick-populated areas, each individual should be inspected at the end of the day to look for ticks. Most important are personal protection techniques when outdoors, such as:
- Avoid walking through woods, shrubbery, or tall grasses.
- Use repellents containing DEET.
- Wear light-colored clothing to maximize ability to see ticks.
- Tuck pant legs into socks or boot top.
- Check children and pets frequently for ticks.
Minimizing risk of disease transmission
The two most important factors are removing the tick quickly and carefully, and seeking a doctor’s evaluation at the first sign of Lyme disease. When in an area that may be tick-populated:
- Although ticks are quite small, check for them, particularly in the area of the groin, underarm, behind ears, and on the scalp.
- Stay calm and grasp the tick as near to the skin as possible, using tweezers.
- To minimize the risk of squeezing more bacteria into the site of the bite, pull straight back steadily and slowly.
- Do not use petroleum jelly, alcohol, or a lit match to remove the tick.
- Place the tick in a closed container (for species identification later, should symptoms develop) or dispose of it by flushing it in a toilet.
- See a physician for any sort of rash or patchy discoloration that appears 3–30 days after a tick bite.