Analysis of blood for borreliosis and tick-borne encephalitis: where and how to take, the interpretation of the result
Tick-borne encephalitis can be carried by a person inespecially severe form, which leads to even a fatal outcome. In the early stages it is similar to other dangerous diseases, for example with such as acute poliomyelitis, typhus, tick-borne borreliosis, etc. That is why it is important to make a diagnosis that will show the real cause of the symptoms. In this article, we will understand how and when to take a blood test for borreliosis.
Borreliosis and viral encephalitis are noted in someand the same regions, arise after the tick sucking in the spring and summer, so they need to be differentiated. If an insect is found on the body, the biomaterial should be analyzed immediately, and if the result is positive, take urgent measures within the next four days after the bite, contacting the therapist or infectious disease specialist.
Features of borreliosis and encephalitis
Encephalitis and borreliosis (Lyme disease) are transferredmites in the territory of Russia. These infectious diseases are often confused, although they are radically different. Tick-borne encephalitis is viral in nature, while borreliosis is bacterial. Both ailments affect the central nervous system, but Lyme disease also affects joints, heart muscle and skin. Encephalitis is characterized by an acute form, for borreliosis - a chronic course. Developing, each disease receives pronounced differential symptoms. Determine the infection will help blood test for encephalitis and borreliosis.
What is more common?
In Russia, six to eight thousand new cases of borreliosis are registered each year, and encephalitis is less common-five to six thousand diagnoses.
Tick-borne encephalitis is caused by the virus of the familyflaviviruses (a group of arboviruses), is carried by bites of European forest and taiga Ixodes ticks, although cases of infection through the gastrointestinal tract due to consumption of raw milk of infected animals (sheep, cows, goats) are also recorded. As the virus develops, slow, but often irreversible changes occur in the vessels and shells of the brain.
At first, the disease is not symptomatically expressed, but toThird week there is a temperature increase, muscle and headaches, worsening of appetite, nausea. A quarter of patients feel these signs even later, after a lapse of a month. Over time, the pain becomes stronger, paralysis of the limbs, convulsions, loss of consciousness, disorientation, coma. If there is no help, a fatal outcome may occur. A blood test can help diagnose the disease in a timely manner.
There are several forms of tick-borne encephalitis, depending on various symptoms. The heaviest ones are fixed in the Far East, the lungs predominate in the central European part of Russia.
Is it treated with encephalitis?
Cure encephalitis is possible, but for thisa large number of drugs and methods are required. In this case, there is no definite type of treatment leading to recovery. Therapy is performed exclusively in the hospital with the appointment of pathogenetic, etiotropic and symptomatic drugs. Complexly prescribed drugs that have anti-inflammatory, immunological, antiviral, hormonal, anticonvulsant, neuroprotective, psychotropic and other actions. After that, they are prescribed restorative treatment: they are physiotherapy exercises, psycho-and occupational therapy, speech therapy, etc. For several years there may be seizures, muscle atrophy symptoms, cognitive function degradation and other CNS disorders. Sometimes the consequences can remain for the rest of your life.
It is worth noting that the most effective protectionfrom encephalitis are the human own antibodies, which the body produces after the introduction of the vaccine in the autumn period, six months before the start of the dangerous season. Vaccines that promote rapid prevention are also universally assigned: three doses for twenty-one days, giving up to 97% protection.
A blood test for borreliosis is important, as there is no vaccine for the disease. In addition, a person does not appear stable immunity to the bacteria, he can get sick again.
Lyme disease occurs in humans afteringress of Borrelia bacteria. She immediately undergoes an attack of the immune system and moves to places where immunity can not cope - in the heart, nerve tissue, tendons. For this reason, unlike encephalitis, the acute stage is not observed, and the disease acquires a protracted character. The main distinguishing symptom is migratory annular erythema, which has the form of a spot of bright red color at the site of the bite, which gradually grows in size and forms rings. The skin is peeling and necrosis appears. Other parts of the body may also have erythema, which are allergic in nature. In some forms of the disease, they may not be present at all, but intoxication and fever occur, which makes borreliosis almost indistinguishable from encephalitis. The blood test for tick-borne borreliosis and encephalitis will help differentiate the disease.
In a month, there are symptoms of CNS damage: partial paralysis of the limbs, speech disorders, mood swings. Meningitis may develop. If you do not take any action, a year later begin to progress arthritis, hearing loss, neuralgia, disorientation, severe speech defects.
Carriers of a class of bacteria, to whichbelongs Borrelia, - the same mites that are carriers of encephalitis. The causative agent of Lyme disease lives in the digestive system of the mite, and not in its saliva, therefore it spreads in the human body not immediately. With the timely removal of the insect there is a chance not to get infected.
Borreliosis is treated, the main thing is to avoid the transition to a chronic stage. The patient is prescribed medication, the correct reception of which guarantees recovery.
Lyme disease is not transmitted from person to person, but there is a possibility of transmission from a pregnant woman to a fetus. That's why this disease is sometimes diagnosed in newborns.
A blood test for borreliosis, and encephalitiscan be taken in infectious hospitals, commercial and virology laboratories. The main thing is that the clinic conducts parallel studies of both diseases.
Analyzes for encephalitis
A study of venous blood (taken from the ulnar vein) and a tick removed from the body is performed.There are the following methods of analysis:
- Immunoassay - it establishes the presence of antibodies to the virus in the human blood (two classes: IgG and IgM), due to high sensitivity it makes it possible to see the disease in the early stages.
- PCR-study of a tick, whose task -determine the presence of the DNA of the encephalitis virus in the insect. Suitable for this type of analysis and fragments, if you can not pull the mite completely. In case of infection of the insect, the patient is immediately injected with a special immunoglobulin, suppressing the development of the virus. This method saves about 60%. A stronger protection is provided by routine vaccination. But this does not mean that the patient should give up, since the most important thing is the timely diagnosis and monitoring of one's own well-being.
Antibodies to the virus are produced only through10-14 days, so it's useless to take tests before this time. By the end of the month and for half a year the peak of concentration is holding. The insect must be brought immediately after removal, and if there is a contamination in the patient, the patient should be observed by the doctor, and two weeks later, the analysis (it should be noted that it does not require special preparation, it only requires not to eat four hours before a visit to the laboratory) .
The results of the IgG antibody assay are given inquantitative expression with the appearance in the decoding of the concept of "titer" - the indicator of the concentration of antibodies (for example, 1: 100, 1: 400, etc.). If more than 1: 100, then the immune system responds. If less, then this shows a lack of response, and when the virus penetrates the person will fall ill. The indicator of a healthy organism is from 200 to 400.
The results of a blood test for IgM antibodies havequalitative character: detected or not. If there are IgG values in the blood and no IgM, such results are likely to indicate vaccination. And the presence of both indicators indicates infection. Repeated examination should be repeated in a week to establish an accurate diagnosis.
Blood test for borreliosis
It is rather difficult to see Borrelia, thereforeindirect methods are used. The most acceptable method is serological tests. Venous blood is taken and tested for antibodies to the spirochaete. As a supplement, synovial and cerebrospinal fluid are also studied. The tick must be brought to the laboratory immediately after removal from the body, placing it in a container for biomaterials or in a test tube.
There are several methods of analyzing blood for borreliosis. The decoding is presented below.
- Chemiluminescent immunoassay allowsexamine the serum of venous blood for the presence in it of IgG and IgM to the pathogen. This is the main method of diagnosis, but it needs to be done 2-4 weeks after the bite, when antibodies appear in the blood.
- Immunoblot (western blot) - gives an accurateDiagnosis in patients with symptoms of Lyme disease, but negative results of immunoassay. For example, in those who have already recovered from borreliosis and have preserved antibodies in the blood.
- PCR with real-time detection is used when serological analyzes are not informative.
- PCR-study of an insect makes it possible to find in the mite fragments of DNA of pathogenic pathogens.
Since borreliosis does not develop immediately,you need to take tests at certain times. In haste, a false negative result can be obtained. The peak of antibody concentration is observed after three months. Before you take a blood test for encephalitis and borreliosis, you should stop smoking and not eat for four hours.
The results of the tests can be either qualitative ("detected" or "not detected"), or quantitative, that is, indicating the amount of antibodies.
Interpretation of the IgG antibody assay
The decoding of the values is as follows:
- Less than 10 U / ml - "negative" (no infection or analysis was given in the early period).
- From 10 to 15 - "doubtful."
- Above 15 is "positive". Such a result can also indicate the patient's illness and the patient's presence of bacterial endocarditis, syphilis, mononucleosis or other diseases. The blood test for borreliosis is better to repeat after one or two weeks.
Indicators of IgM antibody testing
The decoding is as follows:
- Less than 18 U / ml - "negative".
- 18-22 - "doubtful".
- More than 22 - "positively". The recommendations are the same as in the previous analysis.
The study with western blot is manifested by bands on the membrane, indicating the presence or absence of antibodies to certain antigens. The method is effective as an additional method.The conclusion can be the following:
- "Positive" - IgM antibodies are present;
- "Negative" - no antibodies;
- "Indefinite" - weak bands, which do not allow to judge the presence or absence of antibodies.
It is impossible to diagnose borreliosis on the basis ofone analysis, because the process of its development is too complicated. It is also necessary to pass in parallel tests for encephalitis, since ticks can be carriers of both diseases.
In the article we examined how blood tests for tick-borne encephalitis and borreliosis are surrendered and deciphered.