Where to do a tick test for encephalitis. Addresses of laboratories and points for the prevention of tick-borne infections

Shoshina Vera Nikolaevna

Therapist, education: Northern Medical University. Work experience 10 years.

Articles written

Their danger is that in the early stages they may not appear immediately and may remain latent for a long time, and also have similar symptoms to other diseases, such as acute polio. That is why it is so important to recognize pathology in time, for which modern medicine has every opportunity.

Of course, a person does not always become infected, even if the tick is a virus carrier, but prevention is never superfluous. The surest way to find out whether an infection has settled in the body is to take a test for m, but not earlier than two weeks after a tick attack, otherwise the result will be false negative. As an emergency aid (before laboratory diagnostics), the patient is given immunoglobulin.

After extraction, the insect is placed in a pre-prepared test tube (container) with a cloth moistened with water. If you don't have tissue, a cotton pad will do. Creating a humid environment is extremely important.

Next, the container is closed and taken to the laboratory for testing of the biomaterial (absence or presence of antibodies to the causative agent of borreliosis or tick-borne encephalitis). If it is not possible to deliver the tick for analysis on the same day, the test tube should be placed in the refrigerator, where the most favorable storage conditions are available for it.

If the tick test for encephalitis is positive, you should immediately contact a specialist for emergency help.

Laboratory research methods

When a tick bites, doctors conduct a blood test for encephalitis and borreliosis. With the help of informative results, it will be easier for the doctor to diagnose a particular pathology.

If there is a suspicion of borreliosis, which is much more difficult to detect in the blood, in addition to the above, it is necessary to carry out certain examinations, since the effectiveness of a blood test is no more than 50%, which is not enough to obtain a high-quality diagnosis.

Indirect studies include:

1. Serological test. Articular or cerebrospinal fluid or venous blood can be taken from the patient. The components are examined for the presence of antibodies to the spirochete.
2. Chemiluminescent immunoassay. Venous blood serum is used for the study to detect IgG and IgM antibodies. With borreliosis, antibodies may appear as early as the 2nd week (less often, the 4th week) after infection. Analysis accuracy is 95%.
3. Immunoblot of venous blood. It is carried out if you need to check those 5% that remain untested by chemiluminescent immunoassay. To confirm the results, it is advisable to take the encephalitis test again. The time of delivery is determined by the doctor.
4. PCR (with detection). Articular and cerebrospinal fluids are examined. It is carried out when serological tests are not informative enough. Allows you to make a diagnosis at an early stage.

Carrying out PCR analysis of the tick is a necessity.

Who tests for tick-borne encephalitis andborreliosis

Analysis for encephalitis and borreliosis can be done in all infectious diseases hospitals and private laboratories.

It is important to take into account the fact that the information content and reliability of research directly depend on the institution where the analyzes are performed. For example, not every public hospital (laboratory) has the ability to conduct expensive research, as it does not have the appropriate equipment. In private clinics, as a rule, such equipment is available, test results are ready much faster, moreover, all work in such institutions is built on making the client feel as comfortable as possible under conditions of stress.

How long will it take for the patient to know the test results? A positive or negative response can be received within 2 days. Express tests are processed in an expedited manner.

Accurate transcript of the examinations performed

Deciphering the results of the received tests is a fundamental factor in diagnosing the disease and its further treatment. If the studies are carried out qualitatively, they can immediately determine whether a person is a carrier of the infection. However, sometimes tests can be controversial, so the amount of antibodies present in the blood needs to be examined.

In decoding tests for encephalitis, which come in quantitative terms, we use the medical term “titer,” which denotes the concentration of antibodies in the blood to a specific virus. It looks like this: 1:100, 1:200, etc. Indicators from 200 to 400 are considered the norm.

If the indicators are above 1:100, this means that the immune system has responded to the virus, perhaps the person has had encephalitis in the past or was recently vaccinated. A titer below 1:100 indicates that the body has not responded, and the chances of developing the disease are quite high.

The immunoassay is interpreted as follows: if there are no IgM antibodies in the blood, but IgG immunoglobulins are detected, this means that the patient has previously been vaccinated. But the presence of both types of immunoglobulins in the body indicates that it has entered the human body. In the case of a positive test when examining a tick, the patient is immediately injected with a specific immunoglobulin that suppresses the development of infection. This is especially important if the first symptoms are absent even after the incubation period.

If there are doubts about the information content of the analysis, a repeat test is performed.

How to correctly decipher research onborreliosis

The breakdown of tests for borreliosis carried out to detect IgG antibodies is as follows (in units/ml):

1. “Positive” – from 15 and above. However, the result will not be reliable if the person previously suffered from bacterial endocarditis, syphilis, or borreliosis itself. In this regard, it is recommended to repeat the analysis.
2. “Doubtful” – from 10 to 15.
3. “Negative” – less than 10. It should be noted that a negative test cannot serve as a guarantee that there is no infection in the victim’s body. Perhaps this result was obtained due to an untimely study.

The analysis for the study of IgM class antibodies is deciphered as follows (in units/ml):

• “positive” – from 22;
• “doubtful” – in the range of 18-22;
• “negative” – below 18.

Immunoblot analyzes indicate the presence of infection in the fluid tested. Using the PCR method (with detection), it is possible to determine whether the virus DNA is present or absent.

As you know, it is within the power of a person to prevent disease. Treatment of encephalitis is very long, and even with successful therapy there is a risk of serious complications. That is why do not neglect timely vaccination, and when in nature, follow basic safety rules - they will allow you to protect yourself from ticks. If you are nevertheless bitten by a tick, do not despair and seek medical help promptly without trying to solve the problem yourself.

Attention! Tick-borne encephalitis and borreliosis!

Tick-borne encephalitis and borreliosis and preventive measures

The tick bite itself is not dangerous, but if the tick is infected with the tick-borne encephalitis virus, or borreliosis, then there is a threat to the health of the victim. Fatalities have been recorded after being bitten by an infected tick, and more than 25% of victims were left disabled.

Did you know that the emergence of ticks from their shelters after winter can last for several months? It is known that the peak release of mites after winter occurs when the buds of birch trees open. The daily activity of ticks is related to illumination (they usually do not attack at night). If it is very hot during the day, then activity is greater in the morning and evening, if the temperature is below 10 - 12 degrees. C - ticks are not active. Ticks do not like humidity (until the dew has dried, they do not attack).

Did you know that if a tick attacks, it “thinks” for 2 hours before launching its proboscis, choosing a place of suction. If you remove a tick before it begins to feed, infection does not occur, so self-examination and mutual examinations must be carried out at least every 2 hours.

Where is the disease registered?

Currently, the disease with tick-borne encephalitis is registered almost throughout the entire territory of Russia, and from those adjacent to the Moscow region - Tver and Yaroslavl. The territory of Moscow and the Moscow region (except for the Taldomsky and Dmitrovsky districts) is free from tick-borne encephalitis.

What are the main signs of the disease?

The disease is characterized by spring-summer seasonality associated with the period of greatest activity of ticks. The incubation (latent) period usually lasts 10-14 days, with fluctuations from 1 to 60 days. The disease begins acutely, accompanied by chills, severe headache, a sharp rise in temperature to 38-39 degrees, nausea, and vomiting. Worrying muscle pain, which is most often localized in the neck and shoulders, thoracic and lumbar back, and limbs. The patient's appearance is characteristic - the face is hyperemic (red), hyperemia often spreads to the torso.

Who is susceptible to infection?

All people are susceptible to infection with tick-borne encephalitis, regardless of age and gender. Persons whose activities involve staying in the forest are at greatest risk: employees of timber industry enterprises, geological exploration parties, topographers, hunters, tourists. City dwellers become infected in suburban forests, forest parks, and garden plots.

How can you protect yourself from tick-borne encephalitis?

Non-specific individual (personal) protection of people includes:

Compliance with the rules of behavior in an area dangerous for ticks (carry out self-examinations and mutual inspections every 10-15 minutes to detect ticks; it is not recommended to sit and lie down on the grass; parking and overnight stays in the forest should be in areas devoid of grass vegetation or in dry pine forests on sandy soils; after returning from the forest or before spending the night, it is necessary to remove clothes, carefully inspect the body and clothing; it is not recommended to bring freshly picked plants, outer clothing and other objects that may contain ticks into the room; examine dogs and other animals to detect and remove them from them attached and sucked ticks);

Wearing special clothing. In the absence of special clothing, you should dress in such a way as to facilitate a quick inspection to detect ticks; wear plain light-colored clothes; tuck trousers into boots, knee socks or socks with thick elastic bands, the outer part of clothing into trousers; Sleeve cuffs should fit snugly to the arm; Shirt collars and trousers should have fasteners or have a tight fastener that ticks cannot crawl under; put a hood on your head, sewn to a shirt, jacket, or tuck your hair under a scarf or hat.

How to remove a tick?

To remove the tick and initially treat the bite site, you should go to a trauma center or remove it yourself.

When removing a tick, the following recommendations must be followed:

Grab the tick with tweezers or fingers wrapped in clean gauze as close to its oral apparatus as possible and, holding it strictly perpendicular to the surface of the bite, turn the tick’s body around its axis and remove it from the skin;

Disinfect the bite site with any product suitable for these purposes (70% alcohol, 5% iodine, alcohol-containing products).

After removing the tick, you should wash your hands thoroughly with soap.

If a black dot remains (severation of the head or proboscis), treat with 5% iodine and leave until natural elimination.

It is recommended to examine the removed tick for infection with Borrelia and the TBE virus in the laboratory. Ticks removed from a person are placed in a hermetically sealed container with a small piece of slightly damp cotton wool and sent to the laboratory. If it is impossible to examine the tick, it should be burned or doused with boiling water.

Measures for specific prevention of tick-borne encephalitis:

Preventive vaccinations against tick-borne encephalitis are carried out for persons of certain professions working in endemic foci or traveling to them (business travelers, students of construction teams, tourists, people traveling on vacation, to garden plots).

Where can I get vaccinated against tick-borne encephalitis?

In Moscow, there are vaccination rooms at clinics.

When should you get vaccinated against tick-borne encephalitis?

Vaccination against tick-borne encephalitis must begin 1.5 months before leaving for a disadvantaged area.

Vaccination with the domestic vaccine consists of 2 injections, the minimum interval between which is 1 month. After the last injection, at least 14 days must pass before leaving for the outbreak. During this time, immunity is developed. After a year, it is necessary to do a revaccination, which consists of only 1 injection, then the revaccination is repeated every 3 years.

If a person does not have time to get vaccinated before leaving, in emergency cases, human immunoglobulin against tick-borne encephalitis can be administered before leaving for an unfavorable area (pre-exposure prophylaxis), the effect of the drug appears after 24 - 48 hours and lasts about 4 weeks.

What should you do and where should you go if you are not vaccinated and a tick bite occurred while visiting an area unfavorable for tick-borne encephalitis?

Unvaccinated persons are given seroprophylaxis - administration of human immunoglobulin against tick-borne encephalitis no later than the 4th day after tick ingestion (around the clock):

Adults at the State Clinical Clinical Hospital No. 2 (Moscow, 8 Sokolinaya Gora St., 15; tel. 8-495-365-01-47; 8-495-366-84-68);

Children at the Children's Clinical Hospital No. 13 named after. Filatova (Moscow, Sadovaya-Kudrinskaya, 15; tel. 8-499-254-34-30).

Where to conduct laboratory testing of ticks?

Tests of ticks for infection with pathogens of natural focal infections are carried out by the Federal Budgetary Institution "Center for Hygiene and Epidemiology in Moscow" (Grafsky per. 4/9 tel. 8-495-687-40-47).

Where can I get a laboratory blood test?

If you receive a positive laboratory test result, you must urgently seek medical help from medical institutions.

You returned from a walk in the forest - and there it is, a tick, hanging on your hand. Let's figure out what to do.

If your region is free from encephalitis, you should not take it lightly to a tick bite. Ticks are three times more likely to transmit another infection - borreliosis, or Lyme disease, which affects the nervous system, skin, heart and joints. There is no need to panic - timely measures will help both prevent and cure both diseases.

STEP 1. REMOVE THE BITTER

The simplest thing is to dial 03 and find out where to drive to have the tick removed. Usually this is a regional SES or emergency room. If you decide to act on your own, prepare a jar or bottle with a tight lid and a cotton swab moistened with water.

First aid for a tick bite can be provided independently. To remove ticks, pharmacies sell devices in the form of tweezers or a small spear. If you don’t have anything like this at hand, tie a strong thread (as close to the skin as possible) and slowly pull the tick perpendicular to the surface of the skin, carefully and smoothly, slightly turning or swaying. Don't pull it out - you'll tear the tick! If this does happen, remove the tick's head like a splinter with tweezers or a clean needle. Wipe the wound with iodine or alcohol, and place the extracted tick in a pre-prepared jar and place it in the refrigerator.

Dripping oil and kerosene onto a tick or burning the tick is pointless and dangerous. The tick's respiratory organs will become clogged, and the tick will regurgitate the contents, increasing the risk of infection.

STEP 2. CHECKING HIS HEALTH

Within two days, the tick must be taken to the laboratory to be tested for infection with borreliosis and encephalitis. Some centers agree to take only whole ticks for analysis. The answer is given in a few hours, maximum two days.

STEP 3. TAKE EMERGENCY MEASURES

If your tick is from an encephalitis-free area, the injection is usually not given: firstly, due to the risk of allergies, secondly, the vaccination itself is still not useful, thirdly, it does not guarantee one hundred percent protection against encephalitis and its complications - a lot depends on the activity of the virus and your immunity.

Additionally, popular immunostimulants are recommended for the prevention of encephalitis: interferon-based drugs (for example, Viferon) and interferon inducers (for example, Arbidol, Amiksin, Anaferon, Remantadine). It is better to start taking them on the first day after a tick bite.

There is no vaccine against borreliosis. Moreover, experts have still not come to a consensus on at what point after a tick bite to take antibiotics and which drugs are more effective. The difficulty is that ticks can transmit both encephalitis and borreliosis at once, and some antibiotics can aggravate the latent course of encephalitis. Therefore, doctors prefer not to begin treatment for borreliosis until they receive the result of a tick test for encephalitis. So if you feel unwell after a tick bite, do not rush to take medications, get advice and get a blood test for infections.

STEP 4. DISPOSAL LATE DOUBTS

The tick has been removed and checked, the region is free of encephalitis, but is your soul still uneasy? You can get checked by taking a blood test from a vein for borreliosis and encephalitis. There is no point in running to the laboratory immediately; the body gives an accurate response to these infections only after days, or even weeks.

If the result is positive, do not panic: firstly, even when infected, the disease does not always develop, and secondly, in most cases it ends in recovery.

If the results are borderline or questionable, it is better to re-test in 1-2 weeks. If more than 2 months have passed since the tick bite, there is no need to worry.

You can take a blood test in infectious diseases hospitals, virology laboratories, and large commercial laboratories.

SCHEDULED ACTIONS

	Tick-borne encephalitis	Tick-borne borreliosis
Symptoms of possible infection	In the first 7-25 days after a tick bite - chills, fever, headache, nausea, vomiting, aches and numbness in the muscles, pain when tilting the head to the chest, photophobia. Symptoms may stop after 3-4 days, but after a few days the condition worsens	In the first 1-1.5 months, you should be wary of symptoms that can appear both simultaneously and separately: * redness of the skin, not immediately after the bite, but after a while; * fever, chills, joint pain
Risk of getting sick	The virus is contained in saliva, which the tick injects in the first minute after the bite. Therefore, you are taking a risk, even if you removed the tick quickly

The study is aimed at identifying antigens and genetic material of pathogens of tick-borne encephalitis and systemic tick-borne borreliosis (Lyme disease) in the ticks under study. It is used for timely diagnosis of diseases, emergency specific prevention and targeted pathogenetic treatment.

What tests are included in this complex:

• Tick-borne encephalitis (TBEV), antigen
• Ixodid tick-borne borreliosis (TBB), RNA determination

Synonyms Russian

Ixodid tick; tick-borne encephalitis; tick-borne encephalitis virus; systemic tick-borne borreliosis (Lyme disease), tick-borne meningopolyneuritis, tick-borne borreliosis, ixodid borreliosis, chronic migratory erythema, erythemal spirochetosis, Bannowart syndrome.

SynonymsEnglish

Ixodes tick; tick-borne encephalitis; tick-borne encephalitis virus; tick-borne borreliosis (Lyme borreliosis); Borrelia burgdorferi.

Research method

• Linked immunosorbent assay: Tick-borne encephalitis (TBE), antigen
• Polymerase chain reaction (PCR): Ixodid tick-borne borreliosis (TBB), RNA determination

What biomaterial can be used for research?

General information about the study:

Tick-borne encephalitis is a viral natural focal transmissible disease characterized by predominant damage to the central nervous system. The causative agent of the disease is an RNA virus belonging to the genus Flavivirus of the Togaviridae family, Arboviruses group . The infection is seasonal (spring-summer) in nature and is transmitted mainly through the bite of ticks, when crushing an embedded insect; nutritional transmission is also possible through infected raw milk of cows and goats. The main reservoir and carrier of the virus are ticks Ixodes persulcatus and Ixodes ricinus. Additional reservoirs of the virus are rodents, wild animals and birds. Tick ​​infection occurs through the bite and blood sucking of infected animals. In this case, the virus penetrates the organs and tissues of the tick, mainly the salivary apparatus, intestines, and genital apparatus, and persists throughout the entire life period of the insects. The causative agent of tick-borne encephalitis is divided into three subspecies: Far Eastern, Central European and Siberian.

The incubation period of the disease lasts from 3 to 21 days, on average 10-14 days. Clinical manifestations are varied. The initial phase of the disease is characterized by fever, headache, myalgia, and possibly nausea, vomiting, and photophobia. Next, a phase of neurological disorders develops, in which the central and peripheral nervous systems are damaged. Depending on the severity of neurological disorders, the following forms of the disease are distinguished: febrile, meningeal, meningoencephalitic, meningoencephalopoliomyelitis and polyradiculoneuritic, two-wave meningoencephalitis. According to the severity, the infection can occur in mild, moderate or severe form, which affects the duration of the disease, the severity of clinical symptoms and variants of the outcome of the disease. In the final phase of the disease, recovery with extinction of neurological symptoms, chronicization of the pathological process, or death of patients may be observed. Possible long-term latent virus carriage, persistence or chronic form of infection.

Systemic tick-borne borreliosis, or Lyme disease, is a natural focal vector-borne disease caused by the Gram-negative bacterium Borrelia burgdorferi of the Spirochaetaceae family. Infection of humans can occur after bites of ixodid ticks, inoculation of Borrelia with tick saliva, or by crushing an invading insect; transplacental transmission of the pathogen from mother to fetus is also possible. The main “reservoir” and carrier of the virus are ticks Ixodes persulcatus, Ixodes ricinus, Ixodes scapularis. Most often, infection occurs during the spring and summer period when ticks are active.

The incubation period of the disease can last from 3 to 32 days, according to some authors up to 60 days. Tick-borne borreliosis has a variety of clinical manifestations. In the first phase of the disease, the phase of local infection, fever, intoxication, headaches, widespread “migratory” erythema at the site of contact of the tick with the patient’s skin, and regional lymphadenitis are noted. During the phase of hematogenous and lymphogenous dissemination of Borrelia, damage to organs and systems is observed with the development of a varied clinical picture of the disease. Damage to the musculoskeletal, nervous, cardiovascular systems, eyes, liver, kidneys, and skin is noted. In this case, the clinical picture of neuritis, radiculitis, encephalitis, arthritis, conjunctivitis, myocarditis develops, and a rash appears outside the site of the tick bite. With the progression of the disease, its complications and untimely application of treatment, the following processes may develop: neurological disorders in the form of meningitis, meningoencephalitis, encephalitis and encephalomyelitis, severe heart damage, recurrent and/or chronic arthritis. It is possible to develop a continuous or recurrent course of the disease, chronic forms of damage to the nervous system.

Due to the fact that the main “reservoir” and carrier of tick-borne encephalitis and systemic tick-borne borreliosis are ixodid ticks, direct examination of ticks is used in laboratory diagnosis and identification of causative agents of these diseases. It is possible to examine specimens of ticks from natural foci of their distribution in order to identify the presence of pathogens, determine the percentage of infected ticks in the surveyed areas, and the quantitative content of the virus in the case of tick-borne encephalitis. It is necessary to study individual specimens of ticks when they bite a person, inoculate a virus or Borrelia with tick saliva, or when crushing an embedded insect. This is important for determining possible tick infection, timely diagnosis of diseases, emergency specific prevention and targeted pathogenetic treatment.

Modern methods for diagnosing pathogens include enzyme-linked immunosorbent assay and polymerase chain reaction (PCR) methods. They make it possible to determine the pathogen antigen even in a minimal volume of the biomaterial under study, are characterized by the speed of obtaining results and have high rates of diagnostic sensitivity and specificity. A feature of the PCR method is the ability to detect genetic material even if its content is low in the biological material being studied. These methods make it possible to quickly determine the presence or absence of infection of ticks with the tick-borne encephalitis virus and/or the causative agent of tick-borne borreliosis. But if the test results are negative and the disease remains suspected, as well as with the development of clinical symptoms, a blood test of patients is recommended. In this case, it is possible to determine antibodies of the IgM and/or IgG classes to pathogen antigens, as well as to identify the genetic material of pathogens using the PCR method.

What is the research used for?

• For complex laboratory diagnosis of tick-borne encephalitis and/or systemic tick-borne borreliosis;
• to determine the infection level of the ticks being studied;
• to determine the content of antigens and genetic material of pathogens of tick-borne encephalitis and/or systemic tick-borne borreliosis in the ticks being studied;
• to determine possible tick infection for the purpose of timely diagnosis of diseases, emergency specific prevention and targeted pathogenetic treatment;
• to determine the presence and percentage of tick infection in the study area in natural foci and during the insect season.

When is the study scheduled?

• When examining a tick after it has bitten a person, crushing the embedded insect, removing the tick, including in a specialized hospital;
• when examining a tick for the purpose of diagnosing antigens and genetic material of pathogens of tick-borne encephalitis and/or systemic tick-borne borreliosis;
• when examining ticks in order to determine the presence and percentage of tick infection in the study area in natural foci and during the insect season.

What do the results mean?

Reference values: negative.

Reasons for the positive result:

• infection of the test tick with tick-borne encephalitis virus;
• infection of the test tick with the causative agent of systemic tick-borne borreliosis;
• infection of the test tick with the virus of tick-borne encephalitis and systemic tick-borne borreliosis.

Reasons for negative results:

• absence of infection of the test tick with tick-borne encephalitis virus and/or systemic tick-borne borreliosis;
• the pathogen content in the test material is below the detection level;
• false negative results.

Important Notes

If the presence of tick-borne encephalitis and/or systemic tick-borne borreliosis is suspected, but if the test results are negative, a blood test of patients is recommended. In this case, it is possible to determine antibodies of the IgM and/or IgG classes to pathogen antigens, as well as to identify the genetic material of pathogens using the PCR method.

Who orders the study?

Clinical blood test: general analysis, leukocyte formula, ESR (with microscopy of a blood smear to detect pathological changes)

Tick-borne encephalitis virus, IgM

Tick-borne encephalitis virus, IgG

Tick-borne encephalitis virus, antigen (in cerebrospinal fluid)

Total protein in liquor

Glucose in cerebrospinal fluid

Borrelia burgdorferi, IgM, titer

Borrelia burgdorferi, IgG, titer

Borrelia burgdorferi s.l., DNA [PCR]

Serological diagnosis of tick-borne borreliosis and encephalitis

Literature

1. Wang G, Liveris D, Brei B, Wu H, Falco RC, Fish D, Schwartz I. Real-time PCR for simultaneous detection and quantification of Borrelia burgdorferi in field-collected Ixodes scapularis ticks from the Northeastern United States / Appl Environ Microbiol. 2003 Aug;69(8):4561-5.

2. Pancewicz SA, Garlicki AM, Moniuszko-Malinowska A, Zajkowska J, Kondrusik M, Grygorczuk S, Czupryna P, Dunaj J Diagnosis and treatment of tick-borne diseases recommendations of the Polish Society of Epidemiology and Infectious Diseases. Polish Society of Epidemiology and Infectious Diseases / Przegl Epidemiol. // 2015;69(2):309-16, 421-8.

3. Virological study of individual specimens of ixodid ticks using microanalysis methods. Guidelines.

4. Tkachev S. E., Livanova N. N., Livanov S. G. Study of the genetic diversity of the tick-borne encephalitis virus of the Siberian genetic type identified in Ixodes persulcatus ticks in the Northern Urals in 2006 / Siberian Scientific Medical Journal, No. 4 (126 ) – 2007.

5. Pokrovsky V.I., Tvorogova M.G., Shipulin G.A. Laboratory diagnosis of infectious diseases. Directory / M.: BINOM. – 2013.

6. Shuvalova E.P. Infectious diseases / M.: Medicine. – 2005. – 696 p.

Tick-borne encephalitis is a transmissible viral disease with pronounced seasonality, depending on the period of activity of ixodid ticks, and natural focality. The causative agent is tick-borne encephalitis virus, belonging to the RNA viruses of the genus Flavivirus. In Russia, tick-borne encephalitis is registered in 46 regions, about 70% of all cases of the disease occur in the Urals and Siberia. In addition, the tick-borne encephalitis virus is widespread in Europe: the Baltic countries, the Czech Republic, Slovakia, Austria, Germany, Sweden, Norway and Finland, and is also found in Kazakhstan, Mongolia, China and Japan.

During the epidemic season in the Russian Federation, about 3,000 cases of the disease are registered annually, the average mortality rate for tick-borne encephalitis is 1.2%. Its most severe forms and mortality rate of about 10% are associated with the Far Eastern genotype of the virus, which circulates mainly in the Far East.

Like many other arboviral infections, in 80–90% of cases, tick-borne encephalitis occurs in an inapparent form; in other cases, variants of the course of the disease of varying severity develop: fever, viral meningitis and encephalitis. The polio form of the disease is also isolated. In an unfavorable scenario, the acute stage of infection turns into a progressive (chronic) form. In most cases, after the focal encephalitic form, persistent disorders of the central nervous system develop.

Indications for examination. Fever, headache, pain in the muscles of the neck and shoulder girdle, nausea, vomiting, flushing of the face, neck and upper body, possible loss of consciousness, delirium, psychomotor agitation and convulsive attack in the presence of an epidemiological history: tick sucking, visiting a forest area, eating raw goat milk.

Differential diagnosis

• Other ixodid tick-borne infections.
• In the chronic form – diseases of the central nervous system of non-infectious etiology.

Material for research

• Blood serum – detection of specific antibodies, isolation of the virus in cell culture;
• blood plasma – detection of virus RNA;
• CSF – detection of viral RNA, isolation of the virus in cell culture;
• whole blood – virus isolation in cell culture.

Etiological laboratory diagnostics include isolation of the virus using cultural methods, detection of virus RNA and its antigens, and detection of specific antibodies to the pathogen.

Comparative characteristics of laboratory diagnostic methods. The cultural method, based on the isolation of the virus from whole blood, blood serum, brain tissue in cell culture (SPEV, Vero, tick-borne cell cultures) and using sensitive laboratory animals, is not used as a routine method in diagnostic laboratories, since it requires compliance with measures biological safety during work associated with the accumulation of a virus belonging to pathogenicity group II.

Detection of antigen virus in the analysis for tick-borne encephalitis using the ELISA method in blood taken during the incubation period, in the absence of a carrier, allows for adequate prevention of tick-borne encephalitis. During the period of acute clinical manifestations, the dynamic determination of hypertension in the blood makes it possible to make a forecast about the possible transition of the disease to a chronic form, and in the case of a progressive course of the disease, to differentiate tick-borne encephalitis from diseases of the nervous system of other etiologies.

Detection of viral RNA by PCR has high diagnostic specificity, but insufficient sensitivity, which does not exceed 50% (relative to the detection of specific antibodies by ELISA); the study is carried out only in combination with the identification of specific antibodies. To detect viral RNA, blood or CSF samples taken in the first week of the acute stage of the disease or, in case of clarification of the persistence of the tick-borne encephalitis virus, are used; brain tissue is examined when deciphering deaths.

Determination of specific IgM and IgG antibodies in blood serum and/or CSF is performed primarily by ELISA. Also, to study the dynamics of titers of the increase in hemagglutinating antibodies in the acute period of the disease, the RTGA method is used. IgM antibodies to the tick-borne encephalitis virus appear from the 3-4th day from the onset of the disease, IgG antibodies - on average on the 10-14th day. Certain difficulties in laboratory confirmation of diagnosis, based on the identification of specific IgM antibodies and dynamic changes in the titer of IgG antibodies in “paired sera,” arise in the case of disease in vaccinated individuals. As a rule, one can observe mainly an increase in IgG antibodies. In this case, it is advisable to use methods of direct detection of the pathogen: virus isolation, detection of virus RNA or its antigens.

The neutralization reaction (RN) is the most specific reaction for detecting AT. A limitation to the use of this method is the need to work with live virus and adhere to appropriate biosafety precautions.

Features of interpretation of laboratory research results. Detection of RNA of the tick-borne encephalitis virus in the patient’s blood and CSF is the basis for a preliminary diagnosis; detection of an increase in antibody titers to the tick-borne encephalitis virus in blood samples taken over time (paired sera) serves as confirmation of the etiology of the disease.

The danger of getting a tick bite lies in wait for a person everywhere - when going for mushrooms in the forest, walking in the park, traveling to the country. Being on the branches of trees and in the grass, they can get on a person, and he may not even realize it for some time.

Ticks are not as harmless as many other insects, so everyone should be aware of the serious diseases they carry. These include:

1. Tick-borne encephalitis is a natural focal infection of a viral nature, which is characterized by a feverish state, poisoning of the entire body and damage to the gray matter of the brain. At first, for several days, the disease may be completely asymptomatic. Only by 3–4 weeks does the temperature rise significantly, nausea and loss of appetite, severe headaches, convulsions and even paresis of the limbs, coma. If you do not provide qualified medical care, everything can end in death.
2. Borreliosis (or Lyme disease) is the most common infection transmitted by ticks. The disease affects the central nervous system, joints, skin and heart muscle. Often, in almost 50% of cases, it becomes chronic. .
3. Congo-Crimean hemorrhagic fever is a serious disease spread by ticks, which results in intoxication and bleeding.
4. Omsk hemorrhagic fever is a viral focal disease with fever, damage to the respiratory organs and hemorrhage syndrome.
5. Hemorrhagic fever with renal syndrome - to other symptoms is added severe kidney damage, and even the development of acute renal failure.

For security reasons, you cannot:

• pick up a tick with unprotected hands - if it is contagious, you can also become infected through cracks in the skin;
• pick at the tick wound with sharp objects;
• make sudden movements when removing, squeeze the tick;
• you should fill the wound and smear it, burn the attached tick in the hope that it will come out on its own;
• comb the affected area.

In any case, it is not time to panic - in 80% of cases, even if the tick was infected, it does not cause infection in humans. To eliminate all doubts, blood tests are performed.

There are several analysis methods:

1. PCR is a polymer chain reaction method that detects the causative agent of a disease in blood or other liquid. The method is able to identify the pathogen, even at its lowest concentration in the blood and in the shortest possible time. It is carried out very quickly - laboratory technicians only need a few hours. Blood is taken from a finger. The disadvantage is that you will need specific equipment, which is not available in every hospital. This analysis is not advisable to use when detecting encephalitis - if there is a positive phase of immunoglobulin M, it often gives a negative result.
2. ELISA - enzyme immunoassay detects antibodies to the pathogen in the blood, first immunoglobulins M, which appears very first after infection. They represent the body's primary immune response to foreign antigens. Then immunoglobulins G are detected; they will be present in the blood for a long time, since their main task is to resist the reappearance of foreign antigens. This method is very reliable, which is an undeniable advantage. The downside is that blood is taken from a vein, which is not very practical with small children.
3. Western blotting is similar to ELISA, but has even higher accuracy, especially when identifying borreliosis and in order to separate it from encephalitis - this method is 100% accurate. Unlike ELISA, which detects the total amount of immunoglobulins, this study can even detect antibodies to specific pathogen genes. The result of the analysis is presented in the form of stripes on a test strip: positive, negative, doubtful (undefined type of strip). It is carried out as an additional one. It will take 6 days to wait for the results of such a study. Disadvantages also include the high cost of this method, the high probability of uncertain results (especially when it comes to patients with immunodeficiency conditions) and the need for highly qualified laboratory assistants.
4. Chemiluminescent immunoassay MPA for borreliosis. Venous blood serum is examined. It is this method that gives the most accurate diagnosis, reliability is over 95%. It is important to carry it out within 2–4 weeks after the bite. Antibodies peak only after 3 months.
5. RIF – radioenzyme immunoassay. Fast and inexpensive, but increasingly losing its relevance and giving way to new techniques.
6. Immunofluorescence blood test is the most accessible of all. Many hospitals provide this. To establish an infection, blood serum, cerebrospinal fluid, and joint fluid are used. When a virus is detected, complexes labeled with fluorescein begin to glow when viewed through a special microscope.

Tests for G antibodies are either qualitative (simply “yes” or “no”) or quantitative, with numbers of antibodies detected.

• Less than 10 units/ml – absence of disease or too early;
• 10–15 – doubtful;
• 15 and above – positive. Moreover, this is possible if you have previously suffered from syphilis, mononucleosis, and others. The analysis is repeated after 1–2 weeks.

For antibodies M:

• Up to 18 units/ml – negative;
• 18-22 – doubtful;
• More than 22 – positive.

The infectious diseases hospital will tell you what tests to take after a tick bite.

An analysis is performed to confirm or refute the disease. But this is not done immediately after the bite - such an examination does not provide any necessary information.

When to take a blood test after a tick bite:

1. The greatest reliability is provided by examinations carried out after 10 days - this is if the analysis is done using the PCR method.
2. If the ELISA method is used, then blood is donated only after 4–5 weeks.

Antibodies M and G appear in the blood only after 2–4 weeks. The material must be taken exactly on time because, for example, borreliosis does not appear in the blood immediately. If you do not comply with the deadlines, a false negative result is likely.

Blood must be donated twice for hidden infections. The first - within the period established by the disease, and the second a month after the first. Moreover, the same method must be used both times. A repeat test is not done if the first one is positive.

How long does it take to analyze the tick itself?

No less important is the examination of the bitten tick itself. As mentioned, it is not kept in the jar for more than 24 hours from the time it is removed. For microscopic examination it must be a living insect.

It’s a completely different matter with PCR - it’s good even if it’s dead, even just a small part is enough and it’ll be good for 3 days. When a tick is delivered to the laboratory, it should be specifically instructed that it be examined simultaneously for all possible infections.

How much tick analysis is done depends on the laboratory and equipment. Most often, such an analysis is done within 3 days. In private clinics, it is possible to complete the study in 12 hours. You can store the tick at a temperature of strictly +5 degrees for two days.

How many days after a bite should you donate blood?

To identify borreliosis, it is very important to monitor the dynamics of blood tests. The analysis is taken twice: the first time must be 10 days after the bite, and the second time 2-3 weeks after. Repeated analysis is necessary to determine the effectiveness of treatment. Laboratory detection of the borreliosis virus is carried out in the following cases:

• when there is a tick on the body, and even more so – several;
• when the bite took place in an epidemic zone;
• if it is discovered that the tick is a carrier of the virus;
• when the patient has symptoms of the disease;
• to differentiate one disease from others with similar symptoms (for example, meningitis);
• to determine how effective the prescribed treatment was;
• in order to confirm the diagnosis.

Blood is drawn from a vein in the morning on an empty stomach. It is advisable not to smoke for at least an hour before the test.

Returning to the question of what tests are taken for a tick bite, it is important to remember one thing: sometimes, although very rarely, borreliosis and encephalitis can develop simultaneously, so you need to take everything at the same time.

Populations of these insects live in any climate zone throughout Russia. This means that anyone can become a potential victim of this insect. Of course, the best option is timely. But, in any case, after being bitten, you should not panic, but strictly follow the instructions and get tested to detect diseases transmitted by ticks.