| 释义 |
Lyme disease
Lyme disease L0172400 (līm)n. An inflammatory disease caused by a spirochete (Borrelia burgdorferi) that is transmitted by ticks and usually characterized by an initial rash followed by flulike symptoms including fever, joint pain, and headache. If left untreated, the disease can result in chronic arthritis and nerve and heart dysfunction.
[After Lyme and Old Lyme, , towns in southeast Connecticut where the diagnosis of an unusually high number of juvenile arthritis cases in 1975 led to the identification of the disease.]Lyme disease (laɪm) n (Pathology) a disease of domestic animals and humans, caused by the spirochaete Borrelia burghdorferi and transmitted by ticks, and variously affecting the joints, heart, and brain[C20: named after Lyme, Connecticut, the town where it was first identified in humans]Lyme′ disease` (laɪm)
n. a chronic, recurrent inflammatory disease characterized by joint pains, fatigue, and sometimes neurological disturbances, caused by a tick-borne spirochete, Borrelia burgdorferi, that often induces a transient bull's-eye reddening of the skin at the site of infection. [1982; earlier Lyme arthritis (1976), after Lyme, Conn., where an outbreak was studied (1973–75)] Lyme disease (līm) A disease caused by bacteria that is transmitted by a species of tick called a deer tick. It begins as a large red spot at the site of the tick bite and is usually followed by chills, fever, and fatigue, often lasting for several weeks.Lyme diseaseA disease caused by bacteria transmitted by bites from ticks. It results in arthritis, especially in the knee joint.Thesaurus| Noun | 1. | Lyme disease - an acute inflammatory disease characterized by a rash with joint swelling and fever; caused by bacteria carried by the bite of a deer tickLyme arthritiszoonosis, zoonotic disease - an animal disease that can be transmitted to humans |
TranslationsLyme disease
Lyme disease or Lyme borreliosis, a nonfatal bacterial infection that causes symptoms ranging from fever and headache to a painful swelling of the joints. The first American case of Lyme's characteristic rash was documented in 1970 and the disease was first identified in a cluster at the submarine base in Groton, Conn., by Navy doctors who reported their findings in 1976. It became more widely known and received its common name when it struck a group of families in nearby Lyme, Conn. In the United States the disease occurs mainly in the Northeast and parts of the Midwest among people who frequent grassy or wooded areas, but black-legged ticks are found in roughly half the counties in the United States. The disease is also prevalent in N and central Europe and temperate Asia. It is caused by the spirochetes of the genus Borrelia and is transmitted by black-legged, or deer, ticks of the genus Ixodes, which live on deer, mice, dogs, and other animals. The bite of the tick injects the bacteria into the blood. A red rash develops, often circular with a bull's-eye appearance, followed by flulike symptoms (fever, headache, and painful joints). Most people are successfully treated with antibiotics. A small number develop chronic disease with neurological problems, memory loss, arthritis, and eye inflammation. Lyme disease is sometimes accompanied by babesiosisbabesiosis
, tick-borne disease caused by a protozoan of the genus Babesia. Babesiosis most commonly affects domestic and wild animals and can be a serious problem in cattle, but since the mid-20th cent. the disease has also been found in humans.
..... Click the link for more information. or human granulocytic ehrlichiosisehrlichiosis
, any of several diseases caused by rickettsia of the genera Ehrlichia and Anaplasma. Ehrlichiosis is transmitted by ticks. Both human forms tend to develop about nine days after a tick bite.
..... Click the link for more information. , which also infect Ixodes ticks. See also Rocky Mountain spotted feverRocky Mountain spotted fever,
infectious disease caused by a rickettsia. The bacterium is harbored by wild rodents and other animals and is carried by infected ticks of several species that attach themselves to humans.
..... Click the link for more information. . Bibliography See P. Murray, The Widening Circle (1996); A. Karlen, Biography of a Germ (2000); J. A. Edlow, Bull's-Eye (2003). Lyme disease A multisystem illness caused by the tick-borne spirochete Borrelia burgdorferi. The disease, also known as Lyme borreliosis, generally begins with a unique expanding skin lesion, erythema migrans, which is often accompanied by symptoms resembling those of influenza or meningitis. During the weeks or months following the tick bite, some individuals may develop cardiac and neurological abnormalities, particularly meningitis or inflammation of the cranial or peripheral nerves. If the disease is untreated, intermittent or chronic arthritis and progressive encephalomyelitis may develop months or years after primary infection. See Nervous system disorders The causative agent, B. burgdorferi, is a helically shaped bacterium with dimensions of 0.18–0.25 by 4–30 micrometers. Once thought to be limited to the European continent, Lyme borreliosis and related disorders are now known to occur also in North America, Russia, Japan, China, Australia, and Africa, where B. burgdorferi is maintained and transmitted by ticks of the genus Ixodes, namely I. dammini, I. pacificus, and possibly I. scapularis in the United States, I. ricinus in Europe, and I. persulcatus in Asia. Reports of Lyme disease in areas where neither I. dammini nor I. pacificus is present suggest that other species of ticks or possibly other bloodsucking arthropods such as biting flies or fleas may be involved in maintaining and transmitting the spirochetes. See Ixodides All stages of Lyme borreliosis may respond to antibiotic therapy. Early treatment with oral tetracycline, doxycycline, penicillin, amoxicillin, or erythromycin can shorten the duration of symptoms and prevent later disease. See Antibiotic Prevention and control of Lyme borreliosis must be directed toward reduction of the tick population. This can be accomplished through reducing the population of animals that serve as hosts for the adult ticks, elimination of rodents that are not only the preferred hosts but also the source for infecting immature ticks with B. burgdorferi, and application of tick-killing agents to vegetation in infested areas. Personal use of effective tick repellents and toxins is also recommended. See Infectious disease, Insecticide Lyme disease affects not only humans but also domestic animals such as dogs, horses, and cattle that serve as hosts for the tick vectors. Animals affected show migratory, intermittent arthritis in some joints similar to that observed in humans. Lyme disease[′līm di‚zēz] (medicine) A complex multisystem human illness caused by the tick-borne spirochete Borrelia burgdorferi. Also known as Lyme borreliosis. Lyme disease
Lyme Disease DefinitionLyme disease is an infection transmitted by the bite of ticks carrying the spiral-shaped bacterium Borrelia burgdorferi. The disease was named for Lyme, Connecticut, the town where it was first diagnosed in 1975 after a puzzling outbreak of arthritis. The organism 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.DescriptionLyme disease, which is also called Lyme borreliosis, is a vector-borne disease. This term means that 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 Borrelia burgdorferi organism literally inserts it into a host's bloodstream when it bites the host to feed on its blood. It is important to note that neither Borrelia burgdorferi nor Lyme disease can be transmitted directly from one person to another, or from pets to humans.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 Centers for Disease Control and Prevention (CDC) in 2000 were from only nine states (Connecticut, Rhode Island, New York, Pennsylvania, Delaware, New Jersey, Maryland, Massachusetts, and Wisconsin). The disease is also found in Scandinavia, continental Europe, the countries of the former Soviet Union, Japan, and China; in addition, it is possible that it has spread to Australia.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.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, Borrelia burgdorferi 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 themselves 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), they are difficult to spot, giving them ample opportunity to transmit Borrelia burgdorferi while feeding. Although far more adult ticks than nymphs carry Borrelia burgdorferi, 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 Borrelia burgdorferi.Causes and symptomsLyme disease is caused by Borrelia burgdorferi. Once Borrelia burgdorferi gains entry to the body through a tick bite, it can move through the bloodstream quickly. Only 12 hours after entering the bloodstream, Borrelia burgdorferi can be found in cerebrospinal fluid (which means it can affect the nervous system). Treating Lyme disease early and thoroughly is important because Lyme disease 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 many people who are exposed to Borrelia burgdorferi 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 Lyme disease) and whether Borrelia burgdorferi is localized or disseminated (spread through the body by fluids and cells carrying Borrelia burgdorferi). 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 diseaseThe 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 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 outward. About 75% of patients with Lyme disease develop EM. 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 people with dark skin. Of those who develop Lyme disease, 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 three days and disappears only days later.Late disseminated disease and chronic lyme diseaseWeeks, 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).
- Arthritis (short episodes of pain and swelling in joints) and other musculoskeletal complaints. Arthritis eventually develops in about 60% of patients with untreated Lyme disease.
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). Lyme disease accounts for more than 90% of all reported vector-borne illnesses in the United States. It is caused by an infection transmitted by the bite of ticks carrying the Borrelia burgdorferi bacterium. (Data taken from the Centers for Disease Control. Illustration by Electronic Illustrators Group.)DiagnosisA 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 kyme 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.In February 1999 the Food and Drug Administration (FDA) approved a new blood test for Lyme disease called PreVue. The test, which searches for antigens (substances that stimulate the production of antibodies) produced by Borrelia burgdorferi, gives results within one hour in the doctor's office. A positive result from the PreVue test is confirmed by a second blood test known as the Western blot, which must be done in a laboratory.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.TreatmentThe treatment for Lyme disease is antibiotic therapy; however, overprescribing of antibiotics can lead to serious problems, so the decision to treat must be made with care. Disease organisms can develop resistance to families of medications over time, rendering the drugs useless. Furthermore, testing and treatments can be expensive. If a patient has strong indications of Lyme disease (symptoms and medical history), the doctor will probably begin treatment on the presumption of this disease. The American College of Physicians recommends treatment for a patient with a rash resembling EM or who has arthritis, a history of an EM-type rash, and a previous tick bite.The benefits of treating early must be weighed against the risks of over treatment. The longer a patient is ill with Lyme disease before treatment, the longer the course of therapy must be, and the more aggressive the treatment. The development of opportunistic organisms may produce other symptoms. For example, after long-term antibiotic therapy, patients can become more susceptible to yeast infections. Treatment may also be associated with adverse drug reactions.For most patients, oral antibiotics (doxycycline or amoxicillin) are prescribed for 21 days. 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. Corticosteroids (oral) may be prescribed if eye abnormalities occur, but they should not be used without first consulting an eye doctor.The doctor may have to adjust the treatment regimen or change medications based on the patient's response. Treatment can be difficult because Borrelia burgdorferi comes in several strains (some may react to different antibiotics than others) and may even have the ability to switch forms during the course of infection. Also, Borrelia burgdorferi can shut itself up in cell niches, allowing it to hide from antibiotics. Finally, antibiotics can kill Borrelia burgdorferi only while it is active rather than dormant.Alternative treatmentSupportive therapies may minimize symptoms of LD or improve the immune response. These include vitamin and nutritional supplements, mostly for chronic fatigue and increased susceptibility to infection. For example, yogurt and Lactobacillus acidophilus preparations help fight yeast infections, which are common in people on long-term antibiotic therapy. In addition, botanical medicine and homeopathy can be considered to help bring the body's systems back to a state of health and well being. A Western herb, spilanthes (Spilanthes spp.), may be effective in treating diseases like LD that are caused by spirochetes (spiral-shaped bacteria).PrognosisIf 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 long-term 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 Borrelia burgdorferi (babesiosis and ehrlichiosis, for instance) may be responsible for treatment failures or more severe symptoms. Most fatalities reported with Lyme disease involved patients coinfected with babesiosis.PreventionUpdate on vaccinationA 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 exposurePrecautions to avoid contact with ticks include moving leaves and brush away from living quarters. Most important are personal protection techniques when outdoors, such as:- Spraying tick repellent on clothing and exposed skin.
- Wearing light-colored clothing to maximize ability to see ticks.
- Tucking pant legs into socks or boot top.
- Checking children and pets frequently for ticks.
In highly tick-populated areas, each individual should be inspected at the end of the day to look for ticks.Minimizing risk of diseaseThe two most important factors are removing the tick quickly and carefully, and seeking a doctor's evaluation at the first sign of symptoms of Lyme disease. When in an area that may be tick-populated:- Check for ticks, 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 a tweezer.
- To minimize the risk of squeezing more bacteria into the bite, pull straight back steadily and slowly.
- Do not try to remove the tick by using petroleum jelly, alcohol, or a lit match.
- Place the tick in a closed container (for species identification later, should symptoms develop) or dispose of it by flushing.
- See a physician for any sort of rash or patchy discoloration that appears three to 30 days after a tick bite.
Key termsBabesiosis — A disease caused by protozoa of the genus Babesia characterized by a malaria-like fever, anemia, vomiting, muscle pain, and enlargement of the spleen. Babesiosis, like Lyme disease, is carried by a tick.Bell's palsy — Facial paralysis or weakness with a sudden onset, caused by swelling or inflammation of the seventh cranial nerve, which controls the facial muscles. Disseminated Lyme disease sometimes causes Bell's palsy.Blood-brain barrier — A blockade of cells separating the circulating blood from elements of the central nervous system (CNS); it acts as a filter, preventing many substances from entering the central nervous system.Cerebrospinal fluid — Clear fluid found around the brain and spinal cord and in the ventricles of the brain.Disseminated — Scattered or distributed throughout the body. Lyme disease that has progressed beyond the stage of localized EM is said to be disseminated.Erythema migrans (EM) — A red skin rash that is one of the first signs of Lyme disease in about 75% of patients.Lyme borreliosis — Another name for Lyme disease.Spirochete — A spiral-shaped bacterium. The bacteria that cause Lyme disease and syphilis, for example, are spirochetes.Vector — An animal carrier that transfers an infectious organism from one host to another. The vector that transmits Lyme disease from wildlife to humans is the deer tick or black-legged tick.Zoonosis (plural, zoonoses) — Any disease of animals that can be transmitted to humans under natural conditions. Lyme disease and babesiosis are examples of zoonoses.ResourcesBooksBeers, Mark H., MD, and Robert Berkow, MD., editors. "Bacterial Diseases Caused by Spirochetes: Lyme Disease (Lyme Borreliosis)." In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.PeriodicalsEdlow, Jonathan A., MD. "Tick-Borne Diseases, Lyme." eMedicine December 13, 2002. http://www.emedicine.com/emerg/topic588.htm.Krupp, L. B., L. G. Hyman, R. Grimson, et al. "Study and Treatment of Post Lyme Disease (STOP-LD): A Randomized Double Masked Clinical Trial." Neurology 60 (June 24, 2003): 1923-1930.Nachman, S. A., and L. Pontrelli. "Central Nervous System Lyme Disease." Seminars in Pediatric Infectious Diseases 14 (April 2003): 123-130.Pavia, C. S. "Current and Novel Therapies for Lyme Disease." Expert Opinion on Investigational Drugs 12 (June 2003): 1003-1016.Susman, Ed. "ANA: Neurological Impairment Seen in Patients Given LYMErix Lyme Disease Vaccine." Doctor's Guide October 16, 2002. 〈http://www.plsgroup.com/dg/220652.htm〉.Wormser, G. P., R. Ramanathan, J. Nowakowski, et al. "Duration of Antibiotic Therapy for Early Lyme Disease. A Randomized, Double-Blind, Placebo-Controlled Trial." Annals of Internal Medicine 138 (May 6, 2003): 697-704.OrganizationsCenters for Disease Control and Prevention. 1600 Clifton Rd., NE, Atlanta, GA 30333. (800) 311-3435, (404) 639-3311. http://www.cdc.gov.Lyme Disease Foundation. One Financial Plaza, Hartford, CT, 06103. (800) 886-LYME. http://www.lyme.org.Lyme Disease Network of NJ, Inc. 43 Winton Road, East Brunswick, NJ 08816. http://www.lymenet.org.National Institute of Allergy and Infectious Diseases (NIAID). 31 Center Drive, Room 7A50 MSC 2520, Bethesda, MD, 20892. (301) 496-5717. http://www.niaid.nih.gov.OtherCenters for Disease Control and Prevention, Division of Vector-Borne Infectious Diseases. CDC Lyme Disease Home Page. http://www.cdc.gov/ncidod/dvbid/lyme/.National Institute of Neurological Disorders and Stroke (NINDS) Fact Sheet. Bell's Palsy. Bethesda, MD: NINDS, 2003.NINDS Information Page. Neurological Complications of Lyme Disease. Bethesda, MD: NINDS, 2003.Lyme dis·ease Avoid the incorrect phrase Lyme's disease.A subacute inflammatory disorder caused by infection with Borrelia burgdorferi, a nonpyogenic spirochete transmitted by Ixodes scapularis, the deer tick, in the eastern U.S. and I. pacificus, the western black-legged tick, in the western U.S. The characteristic skin lesion, erythema chronicum migrans, is usually preceded or accompanied by fever, malaise, fatigue, headache, and stiff neck. Neurologic, cardiac, or articular manifestations may occur weeks to months later. Tick nymphs are thought to be responsible for about 90% of transmission to human beings. Nymphs and larvae feed especially on the white-footed mouse, Peromyscus leucopus, while the preferred host of adults is the white-tailed deer, Odocoileus virginianus. Infected reservoir animals and ticks do not become ill. Residual articular or neurologic symptoms, which may persist for months or years after the initial infection, presumably reflect an immune response to the organism. Variations in clinical features or severity from one patient to another may be due to inborn variations in immune response, perhaps linked to the human lymphocytic antigen (HLA) system. Synonym(s): Lyme borreliosis [Lyme, CT, where first observed] About 18,000 cases of Lyme disease are confirmed annually in the U.S. The largest proportion of cases occur in people aged 5-9 years and 50-59 years. States with the highest incidence are Connecticut, Rhode Island, and New Jersey. Lyme disease is generally benign and self-limited even without treatment. Antibody studies in endemic areas suggest that as many as 50% of people who contract the infection never show symptoms. The case fatality rate is virtually zero. The diagnosis is essentially clinical. Serologic tests for antibody to Borellia burgdorferi are notoriously poor in both sensitivity and specificity. In nonendemic areas, false positive test results statistically outnumber true positives. Because IgM antibody appears and peaks relatively late, one half of patients are seronegative during the first month following appearance of the rash. Antibiotic treatment administered early can alter or prevent the expected acute immune response. IgG antibody persists for months or years after infection and hence affords no help in diagnosing acute disease. Given the nonspecific and variable clinical picture and the unreliability of laboratory diagnostic measures, it is inevitable that many cases of Lyme disease are missed, and that, conversely, the diagnosis is often wrongly made. The drug of choice is doxycycline administered orally for several weeks. Amoxicillin is the standard alternative for children and pregnant patients. Recovery does not confer immunity to future attacks. In fact, in highly endemic areas, the reinfection rate may be as high as 20%. Infectious disease authorities do not recommend antibiotic prophylaxis after a tick bite, even in endemic areas, nor do they countenance treatment of asymptomatic people who have serologic evidence of past infection. A vaccine consisting of lipidated outer surface protein A (OspA) of B. burgdorferi synthesized by a nonvirulent strain of recombinant Escherichia coli induces formation of antibody that enters a feeding tick and binds any spirochetes present, preventing their mobilization. However, because of low demand the vaccine was withdrawn from the market by the manufacturer in 2002. Lyme disease (līm)n. An inflammatory disease caused by a spirochete (Borrelia burgdorferi) that is transmitted by ticks and usually characterized by an initial rash followed by flulike symptoms including fever, joint pain, and headache. If left untreated, the disease can result in chronic arthritis and nerve and heart dysfunction.Lyme disease An infection by Borrelia burgdorferi, acquired from tick bites. Lyme disease symptoms may resemble an anxiety disorder and include fatigue, concentration difficulties and/or joint pain; the clinical findings may be mediated by IL-1.
Epidemiology
25–30,000 cases occurred in the US in 2010, making it the most common zoonosis in the US, especially along the Eastern seaboard; B burgdorferi has also been found in Northern Europe and Australia.
Vectors
Deer tick (Ixodes dammini), Eastern USA—up to 60% carry the spirochete; white-footed mouse tick (I pacificus), Western US—±1% carry the spirochete; wood tick (I ricinus), Europe; Lone Star tick (Amblyomma americanum); and rarely in deerflies and horseflies.
Host
Deer mice, field mice.
Lab
Nonspecific findings include increased ESR, IgM cryoglobulins, decreased C3 and C4, increased IgG and IgM antibody titers to B burgdorferi; definitive diagnosis requires identification of IgG antibodies to B recurrentis by the “Western” tick (immunoblot).
Prognosis
60% of untreated subjects develop recurring arthritis—chronic Lyme arthritis—lasting up to years after infection.
Serology
May be positive in patients who are also infected with Ehrlichia spp, which may be due to a co-infection with the same tick bite; PCR for human granulocytic ehrlichiosis is required to confirm the latter infection.
Management
1 month of doxycycline or amoxicillin or 2 weeks of IV ceftriaxone or penicillin.
Vaccine
Osp A vaccine.
Lyme disease stages
Stage I
Erythema chronicum migrans–rash stage, associated with wood tick bites and confined to Northern Europe until 1970 when the first US cases were described, presenting as a solitary reddish papule and plaque with centrifugal expansion (up to 20 cm), peripheral induration and central clearing, persistis for months to years; potentially pruritic with IgM and C3 deposition in vessels; first described in 1910 by Afzelius.
Stage II
Cardiovascular–myocarditis, pericarditis, transient atrioventricular block, ventricular dysfunction; neurologic—Bell’s palsy, meningoencephalitis, optic atrophy, polyneuritis symptoms.
Stage III
Lyme disease may be accompanied by headache, stiff neck, fever and malaise that is subsequently manifest as migratory polyarthritis, intermittent oligoarthritis, chronic arthritis of the knees, chronic meningoencephalitis, cranial or peripheral neuropathy, migratory musculoskeletal pains or cardiac abnormalities.Lyme disease Lyme borreliosis, Primary lyme disease Infectious disease An infection by Borrelia burgdorferi, possibly mediated by IL-1 Epidemiology 8000 cases were reported in 1993–US, making it the most common zoonosis in the US; B burgdorferi has been identified in Northern Europe, Australia Vectors Deer tick–Ixodes dammini, Eastern USA, up to 60% of which carry the spirochete, white-footed mouse tick–I pacificus, Western US, ±1% carry the organism, wood tick–I ricinus, Europe, Lone Star tick–Amblyomma americanum, and rarely deerflies and horseflies Host Deer mice, field mice Lab Nonspecific findings include ↑ ESR, IgM cryoglobulins, ↓ C3 and C4, ↑ IgG and IgM antibody titers to B burgdorferi; definitive diagnosis requires identification of IgG antibodies to B recurrentis by the 'Western'–immunoblot Prognosis 60% of untreated subjects develop recurring arthritis–chronic Lyme arthritis lasting up to yrs after infection Serology may be positive in Pts who are also infected with Ehrlichia spp, which may be due to a co-infection with the same tick bite; PCR for human granulocytic ehrlichiosis is required to confirm the latter infection Treatment 1 month of doxycycline or amoxicillin or 2 wks of IV ceftriaxone or penicillin Vaccine OspA vaccine. See Chronic Lyme disease. Lyme disease stages Stage I Erythema chronicum migrans Rash stage, associated with wood tick bites and confined to Northern Europe until 1970 when the first US cases were described, presenting as a solitary reddish papule and plaque with centrifugal expansion–up to 20 cm, peripheral induration and central clearing, persisting for months to years; potentially pruritic with IgM and C3 deposition in vessels Stage II Cardiovascular–myocarditis, pericarditis, transient atrioventricular block, ventricular dysfunction; neurologic–Bell's palsy, meningoencephalitis, optic atrophy, polyneuritis symptoms Stage III Migratory polyarthritis Lyme disease may be accompanied by headache, stiff neck, fever, and malaise that is subsequently manifest as migratory polyarthritis, intermittent oligoarthritis, chronic arthritis of the knees, chronic meningoencephalitis, cranial or peripheral neuropathy, migratory musculoskeletal pains, cardiac abnormalities Lyme dis·ease (līm di-zēz') An inflammatory disorder typically contracted during the summer and caused by Borrelia burgdorferi, a spirochete transmitted by Ixodes scapularis in the eastern U.S. and I. pacificus in the western U.S., and by various Ixodes species in Europe. (B. valaisiana is another spirochete associated with Lyme disease). The characteristic skin lesion, erythema chronicum migrans, usually is preceded or accompanied by fever, malaise, fatigue, headache, and stiff neck; neurologic or cardiac manifestations, or arthritis (i.e., Lyme arthritis), may occur weeks to months later. Dogs, horses, and cattle are also affected. [Old Lyme, CT, where first observed]Lyme disease (līm) [ Lyme, CT, where a cluster of cases was reported in 1975], LD LYME DISEASE: Classic rash with central clearingA multisystem disorder caused by the spirochete Borrelia burgdorferi and the most common tick-borne disease in the U.S. The disease is endemic in New England, but cases have been reported in all 50 states and in 20 other countries, including Germany, Switzerland, France, and Australia. It occurs most often in the spring and summer, when its deer tick vectors (genus Ixodes) are most active. Prompt removal of visible ticks from the skin before they become attached or gain access to the bloodstream (in the first 24 to 48 hr) decreases the risk of transmission. EtiologyThe infected tick injects its spirochete-laden saliva into the bloodstream, where they incubate for 3 to 32 days and then migrate to the skin, causing the characteristic erythema migrans (EM) rash. DiagnosisThe disease is best diagnosed by the presence of EM, which begins as a red macule or papule at the site of the tick bite and expands in a red ring, leaving a clear center like a target or bull’s eye. The lesion usually feels hot and itchy and may grow to over 20 in (50.8 cm) as more lesions erupt. The lesion is later replaced by red blotches or diffuse urticaria. Conjunctivitis, malaise, fatigue, and flulike symptoms and lymphadenopathy may occur. Antibody tests for Borrelia burgdorferi with an enzyme-linked immunosorbent assay (ELISA) test are also used for diagnosis in patients with a history of exposure and signs and symptoms of Lyme disease but with no evidence of rash. The antibodies are developed against flagellar and outer surface proteins on the spirochete. See: illustration SymptomsThe course of Lyme disease is divided into three stages. 1 localized infection: begins with the tick bite and proceeds as above.2 disseminated infection: begins weeks to months later. The spirochetes spread to the rest of the body through the blood, in some cases causing arthritis (esp. of the knee joints), muscle pain, cardiac dysrhythmias, pericarditis, lymphadenopathy, or meningoencephalitis. Nonprotective antibodies develop during this stage.3 chronic infection: begins weeks to years after the initial bite. Patients develop mild to severe arthritis, encephalitis, or both, which rarely are fatal. TreatmentOral doxycycline or ampicillin (14–21 or –28 day course) effectively eradicates early uncomplicated Lyme disease. Erythromycin or cefuroxime axetil may be administered to patients allergic to penicillin. Patients with cardiac and neurological involvement may need to be treated with intravenous cephalosporins. PrognosisWhen the disease is treated early, results are good. If treated late, convalescence is prolonged, but complete recovery is the usual outcome in most patients. PreventionThe Centers for Disease Control recommends that people should discuss with their health care providers the possibility of getting a Lyme disease vaccination if they are between 15 and 70 years old; live, work, or vacation in endemic areas; or frequently go into wooded or grassy areas. The vaccine is not recommended for children, pregnant women, and those who do not live in or visit endemic areas. When planning to spend time in places where ticks may be located, people should wear clothing impregnated with insect repellents, hats, long sleeves, pants tucked into socks, heavy shoes, and a tick repellent containing DEET (N, N-diethyltoluamide). Tick repellent should not be directly applied to an infant or toddler’s skin because of the danger of neurotoxicity. If possible, people should stay on paths and away from high grass or brush. They should check clothing carefully for ticks when leaving those areas although tick nymphs, which are smaller than 1 mm in length, may not be easily seen. Once home, people should remove and wash clothing and check their entire body, esp. the hairline and ankles, for ticks or nymphs. If a tick or nymph is found, it should be carefully removed with tweezers, esp. the head and mouth parts, but the body of the tick or nymph must not be squeezed. The site may then be cleansed with an antiseptic, but should be observed for signs of infection (redness, swelling, pain, rash), and the primary health care provider contacted if infection is suspected. Some people make the mistake of trying to remove ticks or nymphs with alcohol, a lighted match, or petroleum jelly. These measures are ineffective and may increase the risk of transmission of tick-borne diseases. Prophylactic antibiotics generally should not be requested (or given). Although pet dogs may receive Lyme vaccine, they should still be checked to prevent them from bringing ticks into the house. Patient careThe patient is checked for any drug allergies. Prescribed pharmacologic therapy is explained to the patient, including dosing schedule, the importance of completing the course of therapy even if he feels better, and adverse effects. Patients being treated for Lyme disease often require antibiotics for a prolonged period, esp. in advanced stages, which increases their risk for developing adverse effects (e.g., diarrhea). Methods for dealing with these problems are explained. Patients with chronic Lyme disease often require assistance to deal with changes in lifestyle, family interactions, and ability to perform daily activities. Available local and national support groups can assist with such problems. Patients should be made aware that one occurrence of Lyme disease does not prevent recurrences. The U.S. Department of Health and Human Services has made Lyme disease prevention a priority under its program “Healthy People 2010.” Patients can be referred to the Lyme Disease Foundation (860-870-0070; http://www.lyme.org) or the American Lyme Disease Foundation (http://www.aldf.com) for information and support. illustrationLyme disease A disease caused by the spiral organism (spirochaete) Borrelia burgdorferi , and transmitted by the bite of the tick Ixodes dammini . A slightly itchy red spot appears, within a month at the site of the mite bite. This expands to form a ring. Up to 100 other similar spots may soon appear and there is fever, fatigue, headaches, stiff neck, muscle and joint pain and enlarged lymph nodes. The Borrelia organism can affect almost every organ of the body. Several weeks or months after onset, up to 15 per cent of affected people develop nervous system complications such as MENINGITIS, ENCEPHALITIS, nerve paralysis, muscle weakness or shingles-like pain in the skin. Some develop mental illness and others have a profound fatigue and weakness that may last for months or years. The joints are affected in at least half the cases, usually intermittently and mildly, but sometimes severely with joint damage similar to mild RHEUMATOID ARTHRITIS. Heart involvement occurs in about 8%, usually HEART BLOCK but also heart enlargement and inflammation of the heart capsule (PERICARDITIS). Lyme disease can be passed from a mother to her unborn baby, and Borrelia have been found in children with severe congenital defects. If the early skin pattern is recognized and treatment with antibiotics given, all these complications are avoided. Lyme disease was first reported among the inhabitants of Old Lyme, Connecticut, in l975, but is now occurring in Britain and in many other parts of the world.Lyme, city in Connecticut where disease was first recognized. Lyme arthritis - the arthritic manifestations of Lyme disease.Lyme disease - infectious disease spread by tick.Lyme dis·ease (līm di-zēz') Subacute inflammatory disorder caused by infection with Borrelia burgdorferi, a nonpyogenic spirochete transmitted by Ixodes scapularis, deer tick, in eastern U.S. and I. pacificus, western black-legged tick, in Western U.S. Characteristic skin lesion, erythema chronicum migrans, is usually preceded or accompanied by fever, malaise, fatigue, headache, and stiff neck. [Old Lyme, CT, where first observed]Patient discussion about Lyme diseaseQ. what is lyme disease my dog can't seem to get rid of it - anything other than antibiotics for treatment?A. Lyme disease is transmitted through the bite of a tick. Once the dog starts to be affected by the bacteria, Lyme Disease can progress from a mild discomfort to the stage where a dog will be in such joint and muscle pain it will refuse to move; it is not uncommon for an owner to have to carry a sick dog into the animal hospital. Over the span of two or three days a dog can progress from normal to completely unable to walk due to generalized joint pain. In addition to joint damage, the bacteria can affect the dog's heart muscle and nerve tissue. If the disease is diagnosed in time, treatment can cure the dog before permanent joint or nerve damage occurs. Certain antibiotics, such as the Tetracyclines, are very helpful in eliminating the disease. The earlier the antibiotic is started in the course of the disease, the better the patient's chances of a complete recovery.
Q. lyme disease, how long do the effects last? How often do they come back? What helps? A. Lyme disease affects different areas of the body in varying degrees as it progresses. The site where the tick bites the body is where the bacteria enter through the skin. Initially, the disease affects the skin, causing an expanding reddish rash often associated with "flu-like" symptoms. Later, it can produce abnormalities in the joints, heart, and nervous system. Lyme disease is medically described in three phases as: (1) early localized disease with skin inflammation; (2) early disseminated disease with heart and nervous system involvement, including palsies and meningitis; and (3) late disease featuring motor and sensory nerve damage and brain inflammation and arthritis. It takes weeks to months after the initial redness of the skin for its effects to spread throughout the body. Lyme disease can be treated with antibiotics. Lyme disease can be prevented by using tick avoidance techniques.
http://www.medicinenet.com/lyme_disease/index.htm
Hope this helps.
Q. What to do for early Lyme that's not responding to treatment? I came down with Lyme disease three months ago with a bulls-eye rash. Even though it was supposedly a recent case, I already was having Bell's palsy, memory loss, trouble thinking of words, joint arthritis, severe bone pain, and fatigue. I took 100mg doxycycline 2x a day, as my doctor prescribed, for 3 weeks, but still felt bad, so I took it for 3 more weeks. When I stopped after 6 weeks, all my symptoms came back and I kept getting worse. I finally convinced my doctors to give me a refill, and I've been taking the same prescription since then. Any time when I'm late on a dose or eat something with magnesium, I get very sick again. I'm not getting better, I'm merely suppressing the Lyme disease, and it comes back whenever I stop the antibiotics. What can I do to actually get rid of it? Higher dose doxycycline? Another antibiotic? Two antibiotics at once? IV antibiotics? Supplements? (I'm biased against this, but) Rife machines?A. I did test positive for Lyme disease on the ELISA test.
I think it is just disseminated (I've been having Bell's palsy), so maybe I need 400mg doxy/day (200mg 2x a day) in order to reach the proper concentrations to inhibit B. burgdorferi in the CSF. More discussions about Lyme diseaseAcronymsSeelevodopaLyme disease
Related to Lyme disease: Chronic lyme diseaseSynonyms for Lyme diseasenoun an acute inflammatory disease characterized by a rash with joint swelling and feverSynonymsRelated Words |