Mite clinging to a human or an animal which is in the immediate vicinity, and a parasite on it for a few days. They selected the least significant place for fixing - axillary and inguinal folds, knee bends, head, neck, so the detection of the mite in the early days very difficult. It can be detected a few days after it increases in size in a few dozen times.
By itself, the ticks are not the source of the virus - he catches them from sick animals. The total number of infected ticks is approximately equal to 20%, so the bite of an arthropod is not always threatening infection.
What it is?
Tick-borne encephalitis (spring-summer tick-borne meningoencephalitis) - natural focal viral infection characterized by fever, intoxication and defeat the gray matter of the brain (encephalitis) and / or of the brain and spinal cord (meningitis and meningoencephalitis). The disease can cause persistent neurological and psychiatric complications and even death of the patient.
of statistics carry the virus are six ticks of one hundred (the sick from infected individuals can be from 2 to 6% of people bitten).
How do you get infected?
The main reservoir and source of infection are the ticks. As the tick-borne encephalitis virus enters the body of an insect? After 5-6 days after the bite of an infected animal in the natural focus pathogen penetrates into all organs of the tick and is concentrated mainly in the genital and digestive system, salivary glands. There, the virus remains in the whole cycle of insect life, and this is from two to four years. And all this time after a tick bite an animal or human transmission of tick-borne encephalitis occurs.
To catch can, every single resident of the area where outbreaks occur. These statistics are disappointing for a man.
- The natural reservoir of infection can be any animals: hedgehogs, moles, chipmunks, squirrels, and voles and more about 130 species of mammals.
- Depending on the region, the number of infected ticks varies from 1-3% to 15-20%.
- Some species of birds, too, are among the possible vectors - grouse, finches, thrushes.
- According to epidemiology, tick-borne encephalitis distributed from the central part of Eastern Europe to Russia.
- The first peak of the disease is recorded in May and June, and the second - in late summer.
- There have been cases of infection of human tick-borne encephalitis after drinking milk from infected ticks pets.
Ways of transmission of tick-borne encephalitis: transmissible, when they bite an infected tick, and nutritional - after eating contaminated food.
forms of the disease
Symptoms after the attack of the tick encephalitis are very diverse, but each patient's disease usually occurs during a few well-defined features.
Accordingly, there are several basic forms of tick-borne encephalitis:
- Feverish. Tick-borne encephalitis virus hits the central nervous system, manifested only symptoms of fever, namely, fever, fatigue and body aches, loss of appetite, headache and nausea. The fever may last up to 10 days. Cerebrospinal fluid is not changed, the symptoms of the nervous system are absent. The most favorable prognosis.
- Meningoencephalitic. It characterized by lesions of the brain cells, which are characterized by impairment of consciousness, mental illness, seizures, weakness in the limbs, paralysis.
- Meningeal. The virus penetrates the meninges, hitting neurons. At the same time develops a focal form of the disease. In addition to fever, encephalitis symptoms include severe headache, vomiting, photophobia. Develop signs of involvement in inflammation of the meninges - stiff neck. When conducting lumbar puncture in the cerebrospinal fluid can see signs of inflammation: there plasma cells, reduced levels of chlorides and others.
- Poliomieliticheskaya. It characterized by lesions of neurons cervical spinal cord and resembles polio. The patient has persistent paralysis of muscles of the neck and hands, which leads to disability.
A special form of tick-borne infections - a two-wave current. The first period of the disease is characterized by febrile symptoms and lasts 3-7 days. The virus then penetrates the meninges, there are neurological signs. The second period has about two weeks and takes a lot harder than the febrile phase.
Tick-borne encephalitis - Symptoms
The incubation period for vector-borne transmission path lasts 7-14 days, with alimentary - 4-7 days.
To the Far Eastern subtype TBE typical turbulent flow with a high mortality. The disease begins with a sharp increase in body temperature to 38-39 ° C, starting from severe headaches, sleep disturbances, nausea. After 3-5 days of developing nerve damage.
For the clinical symptoms of tick-borne encephalitis European subtype is characterized by biphasic fever. The first phase lasts 2-4 days, it corresponds viraemic phase. This stage is accompanied by nonspecific symptoms, including fever, malaise, anorexia, muscle pain, headache, nausea and / or vomiting. Then comes eight-remission, after which 20-30% of patients followed by a second phase, is accompanied by central nervous system, including meningitis (Fever, severe headache, neck stiffness) and / or encephalitis (various disorders of consciousness, sensitivity disorders, motor disturbances until paralysis).
In the first phase of laboratory revealed leukopenia and thrombocytopenia. Perhaps a moderate increase in liver enzymes (ALT, AST) in blood chemistry. The second phase is generally observed marked leukocytosis in blood and cerebrospinal fluid. Tick-borne encephalitis virus can be detected in the blood after the first phase of the disease. In practice, the diagnosis is confirmed by the detection of specific IgM antibodies in the acute phase of blood or of cerebrospinal fluid, which are detected in the second phase.
What should I do if bitten by a tick?
If the tick has taken root in a person's skin, it should be removed in a medical facility. it is not recommended to do it on their own, as this may damage the body, and do not remove completely. When the hospital near there, and an urgent need to remove the tick, it is necessary to perform the following steps:
- skin copiously smeared with Vaseline or butter (to stop the flow of oxygen to the tick)
- then grab it with tweezers and careful circular movements clockwise extracted from human skin
- after removal it is imperative during the first day after the bite go to the hospital for vaccination - specific donor immunoglobulin is administered intramuscularly to 3 ml.
Diagnostics
Suspected tick-borne encephalitis is possible in case of outings in endemic areas, when bitten by a tick, if you have a fever, headache, neurologic symptoms. But do not put the clinic diagnosis.
In order to accurately confirm the diagnosis, it is necessary to identify specific antibodies -
- immunoglobulin class M to encephalitis (IgM) - presence indicates acute infection,
- IgG - indicates the presence of infection in contact with the last, or the formation of immunity.
If there are two kinds of antibodies - a current infection.
Also determine the virus in the blood by PCR and PCR was carried out liquor. In addition, in parallel define a different infection in the blood - tick-borne Lyme disease.
Tick-borne encephalitis - treatment
All patients compulsorily admitted to hospital. They show strict bed rest. Patients should be in intensive care or supervised by medical staff because of the unpredictability of current pathology. With the development of complications of patients transferred to the ICU.
Drug treatment of tick-borne encephalitis is as follows:
- infusion therapy - glucose solution, Ringer's solution, tri-salts, Sterofundin;
- causal therapy (aimed directly at the destruction of the pathogen) - specific donor immunoglobulin poliglobulin homologous donor, donor leukocyte interferon, reaferon, Laferon Intron-A, neovir etc .;
- glucocorticoids (methylprednisolone, prednisolone) - preparations of this group prevents damage to the brain and spinal cord, decrease their swelling;
- antipyretics - paracetamol, infulgan. Do not use aspirin because of the potential complications of the liver;
- decongestants - mannitol, furosemide, L-lysine aescinat;
- anticonvulsant therapy - sodium oxybutyrate, magnesium sulfate, sibazon;
- substances that improve the microcirculation in the brain - thiotriazolin, trental, dipyridamole, aktovegin;
- neyrotrofiki - complex B vitamins (neyrorubin, milgamma);
- hyperbaric oxygen therapy.
During the recovery period shown physical therapy treatments, massage therapy, classes with rehabilitator.
Features of the application of immunoglobulin
Regarding the use of the immunoglobulin against tick-borne encephalitis, its introduction is considered as the drug emergency prophylaxis immediately after the bite of the parasite. It provides protection against the development of the disease or contributes to its easy portability.
The drug interrupts the viral life cycle in the initial path of infection, prevent its reproduction. The antigenic structure of the immunoglobulin recognizes virus antigen molecules bind and neutralize them (0.1g serum is able to neutralize approximately 60,000 deaths viral doses).
Efficacy is proved when administered during the first days after the tick bite. Further, the efficiency drops sharply, as prolonged exposure to the virus, already affected the body, and the cell walls of the cells - an insurmountable obstacle for our molecular keepers.
If more than 4 days after contact with ticks, a drug to enter dangerous throughout the incubation period of the virus, it will only complicate the disease but does not warn its development.
prevention
The vaccine is used as a specific prevention, which is the most reliable preventive measure. Compulsory vaccination is required for all persons residing in endemic areas or entering into them. The population in endemic areas is approximately half of the total Russian population.
In Russia, the vaccination is carried out abroad (FSME, Entsepur) Or vaccines of the domestic main and emergency circuits. The basic scheme of (0, 1-3, 9-12 months) is carried out, followed by a booster every 3-5 years. In order to form immunity to the beginning of the epidemic season, the first dose is administered in the fall, the second winter. Emergency circuit (two injections at an interval of 14 days) is used for unvaccinated persons traveling to endemic foci in the spring and summer. Extra vaccinated persons immunized only one season (immunity develops in 2-3 weeks), after 9-12 months, they put the third shot.
The RF additionally sucking ticks when administered intramuscularly people unvaccinated immunoglobulin from 1.5 to 3 ml. depending on age. After 10 days the drug is administered repeatedly in an amount of 6 ml. The effectiveness of emergency prevention of specific immunoglobulin needs to be confirmed in accordance with modern requirements of evidence-based medicine.
Each, for the prevention (prophylaxis) should be remembered:
- try to avoid crowded places mites (forest terrain with high grass, country, soda plots);
- in the event of their visit;
- wear clothing, preferably light colors, covering the exposed body sites (with long sleeves, trousers loaded into socks);
- as often as possible to inspect the clothes, after a visit to such places;
- check the body and clothes;
- clothes extend in hot water (to remove the parasite larvae);
- upon detection of the mite, immediately go to the nearest hospital.
To date, tick-borne encephalitis is not incurable and timely detection of the organism does not cause significant damage. The key in this case is exactly the timely detection of the mite, so you should very carefully examine the surface of the skin (especially in children), after visiting the forest.
It should also be remembered that the tick-borne encephalitis is not spread from one patient to another, it is not dangerous, as the viral disease to others.
