Lyme disease test

synonym

Lyme disease test

introduction

In the Lyme disease it is about the most common infectious disease that can be transmitted by ticks. The carriers of this infectious disease are spiral-shaped bacteria, so-called Borrelia, in the Ticks can occur in all regions of Germany. Although Lyme disease is the most common tick-borne disease in Europe, it is the real one The likelihood of infection after a tick bite is rather low. In general, it can be assumed that all people who are bitten by a tick are only approximate 1.5 to 6 percent infect with the pathogen. In addition, it does not necessarily have to be used even after an infection Lyme disease outbreak come. Just approximately 0.3 to 1.4 percent of all infected people actually develop symptoms afterwards.
However, it comes to one outbreak this infectious disease, this is how Lyme disease usually proceeds creeping. After an incubation period (period from infection to onset of the disease), the affected persons typically occur Palm-sized redness in the area of ​​the tick bite on (Erythema chronicum migrans). In addition, those affected by Lyme disease usually notice flu-like symptoms with a slight fever, headache and aching limbs. This first stage of Lyme disease infection is in most cases not diagnosed as such.
An untreated Lyme disease can develop within a period of Weeks to months spread to different tissues. Especially Joints, internal organs, the meninges and nerves are often attacked by the causative pathogens. The second stage of Lyme disease shows up in most cases Paralysis in the area of ​​the facial nerves (Facial nerve) and night back pain. In the third stage of the disease (so-called Neuroborreliosis) the nervous system can be severely impaired. Affected patients may Cranial nerve damage and a inflammation-related paraplegic symptoms develop. With prompt treatment with a suitable antibiotic, however, Lyme disease can treated quickly and effectively become. However, the prognosis depends on the stage at which treatment was initiated.

Diagnosis

If Lyme disease is present, the doctor can often make the diagnosis without a comprehensive test. In addition to the extensive doctor-patient discussion (anamnese) the physical examination can provide an initial indication of the presence of this infectious disease. In these cases, both the description of the symptoms and the examination results can replace a comprehensive test.
Patients suffering from Lyme disease develop a noticeable rash in the area of ​​the bite just a few days to weeks after the tick bite (Erythema chronicum migrans). In addition, flu-like symptoms such as headache, muscle pain and a mild fever can indicate Lyme disease even without a test. If the findings are unclear, various diagnostic measures can help to confirm the suspected diagnosis of "Lyme disease".

(For more information on the rash, see also: "Tick Bite Rash")

Antibody test / antigen test

In this test, special antibodies that target the causative pathogen can be detected in the blood of the affected patient. If the person concerned has had contact with Borrelia, this test will usually be positive. The detection of antibodies in this test shows that the body's own immune system is dealing with the causative agent. However, a positive antibody test does not necessarily mean that the patient must also have borreliosis. Since the immune system is able to fight the bacterial pathogens in many cases, the infectious disease does not have to break out even after the infection.
Borreliosis can only be spoken of when the test for antibodies is positive and corresponding symptoms (for example lymph node swelling, weakness and fever) can be detected. In the case of a negative test for Lyme disease antibodies, however, the presence of this infectious disease can usually be ruled out. The detection of Borrelia antibodies can be done in different ways. After the blood has been taken, the samples must be transferred to a suitable laboratory as soon as possible. Various tests are then available to the laboratory that can help detect antibodies against the pathogen.
In general, there is a difference between simple screening tests (ELISA test) and complicated confirmatory tests (e.g. Immunoblot or Western blot) can be distinguished. The so-called ELISA test (Enzyme-linked immunosorbent assay) is an immunological procedure that is used to detect certain molecules in the blood. In addition to the body fluid to be tested, this Borreliosis test requires a special plate that is equipped with antibodies against specific antigens. After adding the sample, the specific antigen (here the borreliosis antigen) can dock onto the antibodies. Then the test plate must be sprinkled with another antibody directed against the antigen. This antibody is linked to an enzyme which can be detected photometrically. If the borreliosis test by ELISA is positive, the plate begins to glow in a certain light. If the borreliosis test is negative, this color reaction does not occur.

In addition to detecting a borreliosis infection, the ELISA test is also suitable for diagnosing HIV and hepatitis infections. Since this test procedure produces false-positive results in some cases, the ELISA is only a search test. If the ELISA is negative, no further diagnostics need to be attempted. Borrelia infection can be ruled out. If the ELISA is positive, however, a confirmation test should also be carried out.
The so-called immunoblot is particularly suitable for detecting a Borrelia infection. The immunoblot basically represents a simplification of the so-called Western blot.
With Western blot, the patient's blood sample must be centrifuged before the test and the antigens contained in it must be separated electrophoretically. The sample can then be transferred to a nitrocellulose membrane. With the immunoblot, however, the antigens are individually applied to nitrocellulose strips. Antibodies directed against Borrelia from the blood sample can then bind to these antigens and be made visible with a detection antibody (antibodies to which colored particles are bound). If this confirmatory test is also positive, Lyme disease is considered to be practically proven. A negative confirmatory test, on the other hand, indicates an infection that has already been passed through, which may not have caused any symptoms.

In addition to the detection of Borrelia antibodies in the blood, a test of the nerve water may also be useful. This test is particularly useful if the brain or the spinal cord are affected by Lyme disease (so-called Neuroborreliosis; Lyme disease stage 3). The detection of Borrelia-specific antigens or antibodies in the blood and / or nerve water can take several days.

You might also be interested in: Neuroborreliosis can be recognized by these symptoms.

Pathogen detection

Since the detection of Borrelia antibodies, i.e. an antibody test that is positive, does not necessarily mean that the patient is acutely ill with Lyme disease, further test methods can be useful. For example a positive antibody test before, without the affected patient suffering from typical symptoms, no specific treatment should be initiated. In addition, a test for Borrelia antibodies can also be used negative even though the affected patient already has clear symptoms of infection. This can be the case, for example, if the Infection still quite fresh and the normal duration of antibody formation has not been reached. An infection can only be detected in the affected patient if the doctor is able to identify the causative pathogen directly.
However, direct detection of Borrelia using a microscope is usually not possible. For this reason, the so-called Polymerase chain reaction (short: PCR) help to secure the diagnosis. In this test, the genetic material of the pathogen can be reproduced and detected. However, since this Lyme disease test is a very labor-intensive and time-consuming method, the time until diagnosis is correspondingly long. That too Cultivation of the causative pathogens on a special nutrient medium usually lasts from several days to weeks.

LTT

The LTT (Lymphocyte Transformation Test) is one of the latest test procedures in the diagnosis of Lyme disease. In contrast to the usual tests, the LTT does not aim to detect antibodies or Borrelia antigens, but uses the reaction of the body's own immune system to the bacterial pathogens. Since the LTT is a new type of borreliosis test, it can only be carried out in a few specialized laboratories so far. During the LTT, highly purified antigens from different Borrelia structures are used in the laboratory. During the actual test, white blood cells (T lymphocytes) must be isolated from the test person and then vaccinated with specific Borrelia antigens. Those T cells that have docking sites for certain Borrelia antigens on their surface begin to multiply. These T cells are detected using a labeled DNA base that can be measured.

Further test procedures

In addition to the common test methods for detecting a Borrelia infection in patients, there are various tests that help identify the causative pathogen in a tick to prove. Such a test can be applied to the tick after the tick has been removed from the skin. If the tick is infected with Borrelia, it can within a few minutes be determined.

costs

The cost of typical Lyme disease tests is in most cases very high. However, since Lyme disease is a potentially dangerous infectious disease is the cost of a test Both statutory and private health insurances fully cover it. You only have to bear the costs for those test procedures that detect Borrelia directly in the tick. However, a suitable test can already come at a cost of approximately 20 to 30 euros can be acquired.

On-line

In many cases, an initial suspicion of the presence of a Lyme disease be asked. Be for this purpose various self-tests online offered. These tests usually only require the Assessment of the symptoms typical of Lyme disease. People who suspect they have Lyme disease can have such a test evaluated online to see whether the symptoms are typical of the infectious disease.
Borrelia infection is already showing a few days after the tick bite through an extensive Reddening of the skin in the area of ​​the bite site (so-called Erythema chronicum migrans). The for the presence of a Lyme disease typical reddening of the skin is present sharply demarcated and does not itch or hurt. In addition, the affected patients develop within the first few weeks flu-like symptoms such as fever, fatigue, headache and Body aches. In addition, many sufferers can Swelling of the lymph nodes and inflammatory processes in the area of ​​the conjunctiva be detected.
Only several weeks after the infection does the nervous system become impaired with corresponding symptoms. The Lyme disease teststhat can be carried out online usually ask questions in this context Back pain, paralysis and neurological failures. Especially the facial nerve (Facial nerve) is affected early in a Borrelia infection. In the third stage of the disease, the bacterial pathogens also target that Brain and spinal cord over. Affected patients can therefore experience pronounced symptoms of paralysis (so-called Paraplegic symptoms) develop. Also Joint inflammation are not uncommon for Lyme disease in the third stage.