What is Lyme disease?
The term "Lyme disease"
The term "Lyme disease" summarizes various diseases. What they have in common is that they are caused by certain bacteria, the so-called Borrelia bacteria.
In the Borrelia, there are many subspecies, which in turn can trigger different diseases in humans. One of the most common diseases in Europe and the US is Lyme disease. Therefore, in these countries the term "Lyme disease" is usually equated with the disease "Lyme disease". The term "Lyme" goes back to the city of Lyme in the state of Conneticut (USA). Here the disease was first described in 1975.
Transmission of Lyme Disease: The tick bite
The most common way in which the disease-causing Borrelia enter the human body is the tick bite. Only ticks in the intestine of the pathogens can also transmit a Lyme disease. Thus, the risk of contracting with the Lyme disease bacteria depends, among other things, on how many ticks are infected.
In Germany, people can basically become infected in all federal states, but there are regional variations. In addition, the risk of infection is also dependent on the activity of the ticks. From early summer to fall, the risk of infection is greatest. However, tick bites are not excluded even in winter. So far, there is no evidence that the disease can be transmitted from person to person.
Not every tick bite leads to illness
Not every person stung by a ticks infected with borrelia also becomes infected with Lyme borreliosis. The risk of becoming infected with the pathogens also depends on how long the tick has time for its blood meal. If the tick is detected early and removed, the transmission risk is very low. The risk of infection only rises sharply after 12 hours.
But even if the pathogens manage to get from the gut of the tick into the body of the host, an infection in some of the affected by the immune system can be combated so well that the infection can go completely unnoticed. According to estimates, there are currently about 200,000 new cases nationwide per year.
A chameleon among the infectious diseases
Lyme disease is often referred to as a chameleon among infectious diseases because there is no typical disease course. In addition, the symptoms are often difficult to differentiate from those of other diseases.
In about half of the infected persons, a short time after the transmission of the pathogens, a characteristic wandering redness occurs, which is also called erythema migrans. It first appears as a red ring around the puncture site and then moves ever further outwards. An erythema migrans is sometimes accompanied by fever, muscle and headaches.
After several months to years, it may come as a late complication to certain skin lesions, chronic joint discomfort and diseases of the nervous system and the heart.
With early antibiotic therapy good chances of recovery
If symptoms of disease occur after a tick bite, early treatment with antibiotics is very important. These are usually taken in tablet form. Duration and dosage depend on the clinical picture. The earlier you treat, the better late complications can be prevented. Therefore, complications or chronic complaints usually occur only if the disease is not treated early or not properly.
The causative agents of Lyme borreliosis are Borrelia from a group of different bacterial species, the so-called complexBorrelia burgdorferi sensu lato, These are bacteria that primarily infect ticks, birds and mammals.
It is interesting that different types of Borrelia can also cause slightly different clinical pictures. For example, it is known that the ArtBorrelia burgdorferi especially causes joint pain, while in an infection with the speciesBorrelia gariniiprimarily neurological symptoms occur.
Ticks as transmitters
Ticks infected with borrelia are the main vectors of Lyme disease. It is the most common tick-borne disease. In Europe, it is mainly the tick speciesIxodes ricinus (the common wood buck), in the USA the kindIxodes scapularisthat transmit the disease to humans.
The ticks themselves infect themselves with the Borrelia while sucking the blood of small mammals (especially field mice and rats). It is estimated that in most European regions about 10-20% of the Ixodes ricinus ticks are infected with the causative agent of Lyme borrliosis. Nevertheless, the prevalence rate varies regionally and can reach up to 30% in some areas. In Germany, there is currently a particularly high risk of developing Lyme disease in the federal states of Brandenburg, Saxony, Baden-Württemberg and Bavaria.
Ixodes ricinus ticks live on the ground and are found in a low plant up to a height of 70 cm, where they lurk on their host. Humans can therefore be attacked only during low-growth or domestic activities. Ticks can perceive their host with their sense organs up to 15 m distance.
Generally, the tick can transmit Borrelia in all stages of development. Most common, however, is the transmission in the so-called nymph stage in spring and summer, because nymphs are only 1-2 mm in size and therefore easily overlooked. Mature (adult) ticks can also transmit Borrelia and are more likely to be active in autumn and winter.
The tick bite
If a tick gets on its host, it can come in principle at each body point to a trick. In humans, particularly protected areas are often preferred, e.g. the scalp, the armpits, the popliteal fossa, the groin, areas below the female breast or at the belly button.
The tick ticks the skin first and then pushes its stinging apparatus. Then come with the saliva and anti-inflammatory substances in the wound. This inhibits the bleeding and itching of the wound. Finally, the tick anchors itself with the barbs of her stinging apparatus.
An undisturbed blood meal can take up to several days. The tick grows and can assume a multiple of its initial size.
Infection risk depends on several factors
In the transmission of Borrelia to humans, the longer the tick sucks, the greater the risk of becoming infected with the pathogens, as they are in the intestine of the tick. In many cases, a transfer can be made after 24 hours. However, it is always important to remove the tick as soon as possible.
Studies have shown that 5-10% of people who are stung by a tick, become infected with the pathogens. It is estimated, however, that only 1-6% of infected individuals actually have disease symptoms and develop Lyme disease.
An already existing infection with pathogenic Borrelia can be judged by the reaction of the human immune system. In the fight against bacteria, antibodies are liberated (so-called antibodies) that can be detected in the blood for a long time after infection. Evidence is also possible if the person has been infected but is not ill. In Germany, about 6% of women and 13% of men carry antibodies against Borrelia and have thus undergone an infection.
Lyme Disease: Basics, Causes and Contagion
Only a small fraction of the ticks are infected with Borrelia. Of the infected persons, in turn, only up to 6% suffer from Lyme disease. The symptoms that occur are very diverse. Since there is no typical disease course, Lyme disease is also often referred to as a chameleon among infectious diseases.
Roughly speaking, it is still possible to classify the course of the disease in many patients into an early and a late phase, to which a chronic phase may still follow. In many cases, however, not all sufferers go through all the stages. In addition, there may be overlaps of symptoms between the three stages. For many experts, this classification is therefore considered obsolete. Currently, a split into an early phase and a late phase with chronic symptoms is proposed, which is also included in this article.
1. Early phase of the disease
Wandering red or erythema migrans
About 3 to 30 days after a bite with an infected tick, it can come to the so-called "Wanderröte". This erythema described in the art as erythema migrans classically appears in ring form around the puncture site and then spreads on the skin more and more outward. The redness can also occur as a round spot with several centimeters in diameter. However, this redness should not be confused with an allergic reaction to the saliva of the tick, which usually disappears after a few hours to days.
It is important to know that up to 50% of those infected do not develop any redness, even though they have been infected with Borrelia. In this case, other symptoms may give an indication of the infection. For example, a few days after suffering a tick bite, sufferers report tiredness, nausea, swollen lymph nodes and headache and body aches.
The first signs of disease can sometimes occur only weeks to years after the actual infection. The transition to the late stage is then fluid.
The following additional symptoms can be added:
- Muscle aches
- Joint pain and tendinitis
- Sensitivity disorders and paralysis
- a headache
- eye problems
These symptoms do not necessarily have to be chronic, but sometimes appear as relapses in many sufferers. Disease-free intervals alternate with active phases of the disease. In any case, when the symptoms mentioned above occur after a tick bite treat the disease as soon as possible. Once Borrelia has spread throughout the body, it can cause organ and nerve damage that can not be cured.
2. Late phase of the disease: chronic stage
The early phase of Borrelia infection can be followed either directly by the late phase; or it occurs only after a symptom-free interval of several months to years. In some infected individuals, chronic symptoms develop, even without symptoms of an early stage being noticed. As a result, some of those affected may not remember any tick bites or erythema migrans in the past.
After the spread of the pathogens during the early phase, several organs may be affected in the late phase of the disease. This can lead to a wide variety of symptoms.
Amongst others, the following symptoms are the most common:
- chronic malaise and tiredness
- Muscle and joint complaints
- chronic brain and spinal cord inflammation
- Nerve conduction disorders
- mental complaints
- Gastrointestinal complaints
- eye diseases
- heart disease
- Disorders of the urinary tract and genital organs
One of the most common symptoms of this stage is Lyme arthritis, which causes one or a few joints to become inflamed. Above all, inflammation of the knee joint occurs here. Furthermore, as part of a so-called neuroborreliosis, a chronic polyneuropathy can develop, which causes sensory disorders and paralysis. In addition, the so-called acrodermatitis chronica atrophicans can occur as a skin manifestation, in which the skin on the arms and legs becomes thinner and discolored bluish.
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Important questions about symptoms and diagnostics
The many faces of Lyme disease
Many of the symptoms of Borrelia infection are nonspecific and can easily be confused with other conditions. Thus, fever, muscle and limb pain are also typical of a flu. Muscle and joint complaints are often found in rheumatic diseases, and the neurological symptoms of Lyme disease can also resemble those of multiple sclerosis, depending on their severity. Depending on the symptoms, it may therefore be necessary to carry out different examinations to exclude other illnesses.
The diagnosis can also be made more difficult by the fact that many affected people can not remember a tick bite and not necessarily develop the classic symptom of a Wanderröte. In this case, it is especially important for the doctor to inquire into the exact circumstances when the symptoms appear.
An indication of the disease may also be the detection of certain antibodies against Borrelia in the blood. With the help of special methods it is examined whether antibodies of the body were formed to protect against a Borrelia infection. These antibodies are produced by certain immune cells only after contact with Borrelia and are called antibodies. They are directed against components of Borrelia, so-called antigens, and have the goal of rendering the bacteria harmless. For the detection of such borrelia-specific antibodies, indirect test methods therefore use Borrelia antigens to see if antibodies in the subject's blood react with these antigens.
Detection of antibodies in the blood is not always clear
As a rule, Borrelia can rarely be detected in the blood itself. It is much easier to indirectly detect certain antibodies that are formed by the immune system in contact with the pathogens.
The detection of these antibodies, however, only makes sense if there are also appropriate complaints that indicate a recent infection with Borrelia. Because antibodies to Borrelia in the blood just say that the body has already had contact with Borrelia in the past. With the detection of antibodies it can not be differentiated whether the illness is already healed or is currently active and causes the complaints.
Conversely, it may also be that although symptoms of infection are present, but no antibodies to Borrelia can be found. This occurs especially in the early stages of the disease, when the body already has contact with the bacteria, but has not had enough time to train the corresponding antibodies against the pathogen. In this context, one speaks of a "serodiagnostic gap".
Indirect test procedures: there are also hooks here
In the indirect test methods for the detection of borrelia-specific antibodies, it is possible to proceed in two stages. First, an ELISA screening test is performed. Only when this turns out positive, a so-called immunoblot is carried out as confirmatory test. Immunoblots even allow statements regarding the disease stage based on the detected band patterns. Thus, in the early phase of infection, certain antibodies of the IgM type react, which inter alia react with the Borrelia antigens OspC, p4li and VlsE in the test.In the late phase, on the other hand, antibodies of the IgG type, which react with the antigens p83 / 100, p58, p39, VlsE and DbpA, occur more frequently.
However, a problem with the two-stage procedure is that the ELISA test and the immunoblot are two different test methods which can give quite different results. So it may be that antibodies are not detected by an ELISA, but can be found in the immunoblot, and vice versa. It would therefore be recommendable to have both parties carry out both tests.
It should also be noted in indirect testing that test results from different laboratories can not be compared. Findings from different laboratories should therefore be compared only to a limited extent.
Not always succeeds: the direct pathogen detection
Theoretically, the surest evidence of Borrelia infection is the direct detection of bacteria in the culture or the detection of Borrelia DNA. However, this is difficult to do in practice, as the bacterial culture is very complex and not suitable for routine diagnostics; on the other hand, the bacteria can only be isolated from the skin in sufficient quantities at the beginning of the disease.
In the late stages of the disease, the borrelia retreat to places in the body that are difficult to isolate. Occasionally the pathogens in the late phase can be detected only in the synovial fluid in an infestation of the joints or in the cerebrospinal fluid (cerebrospinal fluid) in an infestation of the spinal cord and the brain. A positive pathogen can therefore be regarded as proof of the infection, but a negative pathogen detection does not rule out that an infection is present.
Studies of brain water in neuroborreliosis
If the nervous system is affected by borreliosis (neuroborreliosis), cerebrospinal fluid can be taken in the acute stage of the disease by means of a puncture in the spinal canal (lumbar puncture). This will either recover Borrelia DNA or other evidence of infection with the bacteria. Thus, an increased number of cells, increased protein content and borrelia-specific antibodies in the CSF may be an indication of acute neuroborreliosis. The lack of these hints does not necessarily mean that there is no infection.
Other methods of diagnostics
In addition to the methods described above, the following additional test procedures are currently also available:
- Lymphocyte activation or transformation tests (LTT, ELISPOT)
- PCR or antigen detection from blood or urine
- Direct detection of Borrelia from patient material using light microscopic techniques
- Antibody detection from immune complexes
- Detection of a decreased CD57-positive lymphocyte population
- Visual Contrast Sensitivity Test (VCS)
However, all these diagnostic test methods have in common that there are currently not enough studies available that could show any actual benefit. Therefore, they have not yet been adequately tested and established from a scientific point of view in order to use them in diagnostics to detect a Borrelia infection.
Borrelia infection should be treated as early as possible with antibiotics. In this way, the clinical course can be shortened and complications can be avoided. Also, the involvement of organs with irreparable damage to the nervous system or joints can be prevented. However, even without timely treatment at the onset of the disease, Lyme disease in some cases heals by itself, so it is generally considered to be a disease with a good prognosis.
Pitfalls of antibiotic treatment
Lyme disease is treated with antibiotics. The type of antibiotic, the duration of treatment and the type of administration depend on the stage and the severity of the disease as well as the age of the person affected.
It is important to know that the late-stage disease is much more difficult and protracted to treat than it does in the early stages. It may also happen that an antibiotic is ineffective due to resistance of the bacteria and must be replaced by others, which further delays the overall therapeutic success.
Furthermore, it should be noted that antibiotic treatment is only successful in a well-functioning immune system. If there is an immunodeficiency, it can also come here to difficulties in the therapy.
Therapy in the early phase
Symptoms in the early stages of the disease are treated with doxycycline, Amoxicillin or cefuroximaxetil. Treatment should be for at least four weeks. If neuroborreliosis occurs early in the disease, the antibiotics ceftriaxone, Cefotaxime or penicillin G are administered intravenously.
Therapy in the late phase
The drug of choice in the late phase of the disease is the intravenous administration of the antibiotic Ceftriaxone over two to four weeks. In the case of intolerance or primary involvement of the skin or the nervous system, doxycycline, amoxicillin, cefotaxime or penicillin G may alternatively be used.
Compared to the treatment of Lyme disease in the early phase, the failure rate of therapy in the late phase of the disease is many times higher at about 50%. The reasons for the poor response of antibiotic therapy are not well understood.However, it is suspected that Borrelia acquire certain abilities to escape the immune system, for example, by the formation of non-biologically active cystic permanent forms.
In addition, Borrelia prefer to colonize poorly perfused tissue, e.g. Joint capsules, fascia or tendons. Due to the low blood flow, they can not sufficiently enrich the antibiotics in these tissues, which makes the therapy more difficult.
Alternative therapy options
There are currently no scientifically sound alternative treatment options for antibiotic treatment. However, sufferers can certainly support the effects of antibiotics by strengthening their immune system.
Sufficient sleep, exercise and a balanced diet can therefore increase the efficiency of the treatment. Among other things, it has been shown that so-called micronutrients such as micronutrients. Vitamins or minerals in micronutrient therapy have a positive impact on the body's immune system. In addition, taking probiotics can help protect the gut flora and thus lower the risk of antibiotic-associated diarrhea.
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Questions and answers about treatment and prognosis
Although the immune system produces antibodies after exposure to Borrelia, the infection does not leave a lifelong immunity and therefore does not protect against re-infection with the pathogens. Also, there is currently no vaccine against Borrelia. For this reason, people living in high-risk areas in Europe should always strive to provide sufficient protection against the carrier of Lyme disease, the common wood buck.
As a precautionary measure, stay in grasses and bushes up to a height of 70 cm should be avoided and protective clothing worn. Insect repellents can also provide protection for a while. After staying outdoors, the body should be thoroughly scanned for ticks.
How to remove the tick properly
With a tick bite the tick should be removed as early as possible. It is recommended to apply a light pull on the tick with fine forceps close to the skin. As a result, the tick usually reacts by pulling in the barbs of its stinging apparatus. After a few seconds you should then try again, the tick with the tweezers slowly pull out of the skin.
Turning the tweezers as well as using oil or glue did not help. When turning, you run the risk of not completely removing or squeezing the tick. Using oil or glue can cause the tick to produce more saliva or vomit. Since the pathogens of Lyme disease are in the intestine of the tick, the risk of infection in this approach is only increased.
After removing the tick, the puncture site should be thoroughly disinfected. If residues of the tick nevertheless remain in the skin, one should observe the puncture site well for several months. If it is inflamed or you notice a wandering flush, a doctor should be consulted.
Author: Julia Spengler
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Diagnosis and treatment of Lyme disease. Guidelines of the German Borreliosis Society e.V., Jena. Edition: May 2011.
Lyme Disease: pitfalls in diagnosis and therapy. German Medical Journal. Perspectives of Infectiology 2015.
Bavarian State Office for Health and Food Safety: https://www.lgl.bayern.de/gesundheit/infektionsschutz/infektionskrankheiten_a_z/borreliose/lyme.htm (as of 02.10.2017).