Disease caused by bacteria of the genus Borrelia.
Alternative name: Lyme Disease.
Lyme disease, sometimes referred to as Lyme infection, is a bacterial illness, transmitted to humans by the bite of deer ticks carrying a bacterium known as Borrelia burgdorferi. The disease has been reported in the Northeast, Mid-Atlantic, North Central, and Pacific coastal regions of the United States and in Europe, where it was first described almost 100 years ago. It is most prevalent in the northeastern states of the United States, with about half of all cases clustered in New York and Connecticut.
Lyme disease is a potentially serious and debilitating illness, affecting not just the joints, but all parts of the body. The disease produces many symptoms several of which can imitate other diseases. No two cases of Lyme disease are exactly alike. This is due to unique differences in each person's immune response; variations in the strains of bacteria; the possibility of active co-infections and/or the intensity of a given bacterial load.
Currently, Lyme disease can be found throughout the US, and on every continent in the world. Infection of both people and animals is worldwide.
In the United States, the Centers for Disease Control (CDC) provide a state-by-state count of Lyme disease cases. Cases are based on reports filed by physicians to each state health department. Because many physicians do not file the necessary paperwork, cases of Lyme disease may be seriously underreported. CDC officials currently acknowledge that there is "considerable underreporting" of Lyme disease. With about 17,000 cases reported in 1998, the CDC admits that the actual figure may be easily 10 times that amount.
If treated early and promptly at the onset of illness, Lyme disease symptoms usually resolve. If left untreated or inadequately treated, the disease can progress to a more complicated chronic form. According to the US Centers for Disease Control (CDC) complications of untreated early-stage Lyme disease include: 40%-60% joint disease; 15%-20% neurologic disease; 8% carditis; and 10% or more patients being hospitalized, some with chronic debilitating conditions.
Each year, May is officially recognized as Lyme Disease Awareness Month. During this month, national Lyme Disease Support Groups and advocacy organizations launch awareness campaigns to educate the public about Lyme disease.
Signs and symptoms of Early Local Lyme Disease often starts with flu-like feelings of headache, stiff neck, fever, muscle aches, and fatigue. About 60% of light-skinned patients notice a unique enlarging rash, referred to as erythema migrans (EM), days to weeks after the bite. On dark-skinned people, this rash resembles a bruise.
The rash may appear within a day of the bite or as late as a month later. This rash may start as a small, reddish bump about one-half inch in diameter. It may be slightly raised or flat. It soon expands outward, often leaving a clearing (normal flesh color) in the center. It can enlarge to the size of a thumb-print or cover a persons back.
To be considered local disease the rash must be at the tick bite site with no other major organ system involvement. A rash occurring at other than the bite site in an indication of Disseminated Lyme Disease.
Don't confuse a local reaction to a tick bite, with signs of infection. A small inflamed skin bump or discoloration that develops within hours of a bite and over the next day or two is not likely to be due to infection - but rather a local reaction to the disruption of the skin.
Causes and Risk factors:
Lyme disease is spread when you are bitten by a tick that is infected with B. burgdorferi bacteria. When an infected tick bites you, bacteria travel to the tick's salivary glands and then into your body through your skin. It takes about 24 hours for a tick to attach itself to the skin and begin to feed. The tick generally must be attached to you for about 36 hours in order for it to transmit the Lyme disease bacteria.
In the United States, the two types of ticks that carry Lyme disease bacteria are:
Deer ticks, which spread Lyme disease in the northeastern and upper Midwestern U.S.
Western black-legged ticks, which spread Lyme disease along the Pacific coast-mostly northern California and Oregon.
Dogs, cats, and horses can become infected with Lyme disease bacteria, but they cannot pass the illness to humans. But infected ticks may fall off the animals and then bite and infect humans. Animals may develop symptoms similar to those seen in people, including fever and swollen joints. A vaccine for dogs is available in some states.
There is no convincing evidence that Lyme disease can be spread to humans by insects such as mosquitoes, flies, or fleas
The disease is not contagious and cannot be spread from person to person. But certain precautions should be taken to prevent spread of the illness through ways such as blood transfusions.
The main risk factor for Lyme disease is exposure to ticks that are infected with Lyme disease bacteria. In areas where Lyme disease is widespread, several factors may increase your risk, including:
- People with active Lyme disease should not donate blood, because the bacteria that cause the illness can be transmitted this way. People who were previously treated for the disease may be able to donate blood, but they should check with the blood bank first.
- A pregnant woman may be able to pass Lyme disease to her unborn child, but proven cases are rare. Lyme disease has not been shown to cause birth defects or fetal death.
- There is no evidence that breast-feeding mothers can pass the illness to their babies through breast milk. But a nursing mother who is suspected of having Lyme disease may be asked to stop nursing until she has completed a course of antibiotic therapy. The baby is also watched closely for symptoms of the disease.
Proper diagnosis of Lyme disease is important. A diagnosis of Lyme disease is straightforward if the patient meets the following criteria:
- Spending time outdoors during the warm months of the year when ticks are most active. Most cases of Lyme disease occur in the northeastern United States and Canada when infected ticks are most prevalent-usually between May and November, with peak activity in June and July.
- Working or playing in grassy or wooded areas doing things like gardening or yard work, hiking, camping, hunting, or fishing.
- Having indoor/outdoor pets. They can bring infected ticks into the house. Although dogs and cats can become infected with the Lyme disease bacteria, they cannot pass the illness to humans. But the infected ticks can drop off the animal and then bite and infect a person. Animals may have symptoms similar to those seen in people, including fever and swollen joints. A vaccine for dogs is available in some areas.
- Having a stone fence or a bird feeder near your house. Stone fences often become homes for mice, and mice may feed on spilled seed from a bird feeder. Where there are mice, there are ticks.
If the patient meets all the criteria, except the rash, the doctor may undertake the enzyme-linked immunosorbent assay (ELISA) or the Western Blot test.
Culture: In a few cases, if the patient seeks a diagnosis within the first 2 - 3 weeks, the doctor may take a sample of the skin or of the blood. If Lyme spirochete is present, it may be identified in the laboratory in a culture medium (a substance in which the organism can thrive and reproduce). This is necessary only if a doctor suspects Lyme but the diagnosis is not clear.
Immune Testing: The U.S. Centers for Disease Control (CDC) recommends a two-step process for Lyme disease blood tests:
ELISA and Other Initial Tests: The first tests used are either enzyme-linked immunosorbent assay (ELISA) or an indirect fluorescent antibody (IFA) test: ELISA is the immune test used most often for Lyme disease. (The IFA test is less accurate but may be used when ELISA isn't available.) ELISA measures antibodies that are directed against the B. burgdorferi spirochete. A newer variant is a rapid test (PreVue) that can provide results within an hour. Positive results from any of these tests still require confirmation with a Western blot test. Negative results do not require further testing. Western Blot. If any of these tests is positive or uncertain, they are followed by the Western immunoblot (WB). This test is more accurate and is very helpful in confirming the diagnosis. The Western blot creates a visual graph showing bands of different colors or shading that laboratories use to interpret the immune response. The CDC recommends only these tests. Other tests -- such as urine antigen, immunofluorescent staining, and lymphocyte transformation -- do not have enough scientific evidence to support their use.
Polymerase Chain Reaction (PCR) Test: The polymerase chain reaction (PCR) test detects the DNA of the bacteria that causes Lyme disease. However, it requires technical expertise and expensive equipment, and can be performed only in a few laboratories in the country. The test also has a high risk of false-positive results. Research indicates that blood or urine samples do not provide accurate results, but skin biopsies may be useful in some cases. At this point, the PCR test is reserved for certain patients with specific diagnostic problems. For most patients, standard antibody tests are preferred.
Tests for Neurologic Involvement: Analysis of Spinal Fluid. In patients who have neurologic symptoms, a lumbar puncture (a spinal tap) may be used to test for the bacteria in spinal fluid and may be useful for an early diagnosis of Lyme disease.
- Lives in an area of tick-infestation.
- Has the tell-tale bulls-eye rash.
- Has other symptoms (headache, joint aches, malaise, flu-like symptoms).
Antibiotics are the drugs of choice for all phases of Lyme disease. In nearly all cases they can cure Lyme, even in later stages.
Treating Early Stage Lyme Disease: The early stages of Lyme disease usually involve classic bull's-eye rash (erythema migrans) and flu-like symptoms of chills and fever, fatigue, muscle pain, and headache. In rare cases, patients develop an abnormal heartbeat (Lyme carditis).
All of these conditions are treated with 10 - 28 days of antibiotics. The exact number of days depends on the drug used, and the patient's response to it. Antibiotics for treating Lyme disease generally include:
- Doxycycline: This antibiotic is effective against both Lyme disease and human granulocytic anaplasmosis (HGA) and so is the standard antibiotic for any patient over 8 years old (except pregnant women). Doxycycline cannot be used routinely in children under 8 years old. It is a form of tetracycline and as such discolors teeth and inhibits bone growth. It can also cause birth defects, so it should not be used during pregnancy.
- Either amoxicillin (one of the penicillins) or cefuroxime (Ceftin) -- a drug known as a cephalosporin -- are the alternative treatments for young children and some adults. Amoxicillin is the first choice and also probably the best antibiotic for pregnant women. Unfortunately, many people are allergic to penicillin. In addition, strains of bacteria are emerging that are resistant to penicillins.
- Intravenous ceftriaxone -- another cephalosporin -- may be warranted if there are signs of infection in the central nervous system (the brain or spinal region) or heart. Other types of antibiotics, such as macrolides, are not recommended for first-line therapy.
Side Effects of Antibiotics: The most common side effects of nearly all antibiotics are gastrointestinal problems, including cramps, nausea, vomiting, and diarrhea. Allergic reactions can also occur with all antibiotics, but are most common with medications derived from penicillin or sulfa. These reactions can range from mild skin rashes to rare but severe, even life-threatening, anaphylactic shock. Some drugs, including certain over-the-counter medications, interact with antibiotics. Patients should report to their doctors all medications they are taking.
Treating Late Stage the disease: Most cases of Lyme disease involve a rash and flu-like symptoms that resolve within 1 month of antibiotic treatment. However, some patients go on to develop late-stage Lyme disease, which includes Lyme arthritis and neurologic disease.
Slightly more than half of patients infected with B. burgdorferi develop Lyme arthritis. About 10 - 20 % of patients develop neurologic the disease. A very small percentage of patients may develop acrodermatitis chronica atrophicans, a serious type of skin inflammation. These conditions are treated for up to 28 days with antibiotic therapy. If arthritis symptoms persist for several months, a second 2 - 4 week course of antibiotics may be recommended. Oral antibiotics (doxycycline, amoxicillin, or cefuroxime) are used for arthritis and acrodermatitis chronica atrophicans. (In rare cases, patients with arthritis may need intravenous antibiotics.)
A 2 - 4 week course of intravenous ceftriaxone is used for treating severe cases of neurological Lyme disease. For milder cases, 2 - 4 weeks of oral doxycycline is an effective option.
There is no surgical treatment for Lyme disease. In severe cases of chronic arthritis, removal of the lining of the affected joints (synovectomy) may be needed if the arthritis has not responded to antibiotics.
Medicine and medications:
Lyme disease is a bacterial infection currently treated with a variety of antibiotics. These may include drugs delivered orally, or by intravenous or intramuscular routes.
Oral antibiotics include:
Intravenous antibiotics include:
- Azithromycin (Zithromax).
Intramuscular antibiotics include:
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.