The Problem Of The Season: Ticks Wake Up In Russia

2023 Author: Abraham Higgins | [email protected]. Last modified: 2023-11-27 23:16

The problem of the season: ticks wake up in Russia

Rospotrebnadzor announced the beginning of the tick activity season. So far, cases of infection with tick-borne encephalitis and borreliosis are rare. The peak incidence is still ahead. Every year in our country 8-10 thousand people get sick from tick bites. Residents of central Russia are most often affected by borreliosis, a dangerous infection that can lead to disability. And there is no vaccination yet.

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Rospotrebnadzor announced the beginning of the tick activity season. Every year in our country 8-10 thousand people get sick from tick bites. So far, cases of infection with tick-borne encephalitis and borreliosis are rare. However, this does not mean that the current tick-borne season will be less intense - the peak incidence is still ahead. Residents of central Russia are most often affected by borreliosis, a dangerous infection that can lead to disability. And there is no vaccination yet.

In the Central Research Institute of Epidemiology of Rospotrebnadzor, a scientific and practical seminar “Laboratory diagnosis of borreliosis. Experience in diagnostics, therapy and observation of patients. At the event, leading experts discussed new possibilities for diagnosing borreliosis, therapy standards and world practice experience.

Our country is characterized by such infections as tick-borne boreliosis (Lyme disease), rickettsioses of the group of tick-borne spotted fevers, tick-borne encephalitis, Q fever, human granulocytic anaplasmosis, human monocytic ehrlichiosis, Crimean hemorrhagic fever. But if, thanks to vaccine prevention, the incidence of tick-borne encephalitis in Russia decreased from 4.4 cases per 100 thousand of the population in 2001 to 1.3 per 100 thousand, then the incidence of borreliosis has not decreased for more than 15 years, amounting to 4.58 per 100 thousand. 100 thousand population.

Diagnostics of the borreliosis

The main topics of the seminar were the discussion of protocols for the diagnosis of ixodic tick-borne borreliosis in Russia, Europe, the United States and practical issues of diagnosis and therapy of various forms of borreliosis: Lyme carditis, arthritis, neuroborreliosis. The head of the scientific group for the development of new methods for diagnosing natural focal diseases of the Central Research Institute of Epidemiology, Lyudmila Karan, made a review of Russian recommendations, as well as European and American protocols for the diagnosis and treatment of borreliosis.

In the USA and European countries, there are separate protocols for the diagnosis of borreliosis - for example, the recommendations of the European Union for an agreed response to borreliosis (EUCALB) of the German Society for the Study of Borreliosis (DBG), the International Society for the Study of Borreliosis and Other Vector-borne Infections in the United States (ILADS), etc. In Russia, there are also several documents regulating the diagnosis, treatment and prevention of ixodic tick-borne borreliosis.

Borreliosis is a disease that undergoes several stages, while its diagnosis and treatment at different stages can differ significantly. Therefore, it is so important to agree on a single classification of the disease and its stages, Karan emphasized. If the patient develops erythema migrans (redness on the skin, with an increase in which the center of the spot is cleared), it is recommended in all world protocols to start treatment of borreliosis immediately and not to carry out serological laboratory diagnostics of the disease. In other cases, Russian and foreign recommendations suggest using two-step serological diagnostics.

Two-step scheme

The first stage of diagnosis requires a qualitative or quantitative assessment of the presence of specific antibodies by ELISA. In case of a positive result, the second stage of diagnostics is carried out - determination of the specificity of IgG or IgM immunoglobulins to certain proteins of Borrelia antigens by the method of immune blotting or using an immunochip.

In the United States, they are now trying to introduce a two-step diagnostic scheme, in which ELISA tests are used at both stages. Moreover, if at the first stage the most sensitive and capable of detecting antibodies of the widest possible spectrum ELISA kit is required, then for the second this set should be already the most specific in order to cut off false positive results. These guidelines are also being considered in Europe, but not all reference centers and laboratories follow them yet.

“No indirect method of laboratory diagnostics can confirm the current Lyme infection without the presence of clinical signs characteristic of borreliosis, due to the prolonged persistence of specific immunoglobulins,” summed up Lyudmila Karan. A single detection of IgM antibodies cannot be a marker of an early stage of borreliosis. Therefore, laboratory diagnosis of this infection should be done using several methods or tests.

In addition, for the prevention of the disease and monitoring of infection in its natural foci, PCR studies of the infection of ticks themselves with borrelia are carried out. Several test systems for molecular diagnostics have been registered in Russia, including reagent kits and immunochips developed by scientists from the Central Research Institute of Epidemiology of Rospotrebnadzor.

Antibiotic therapy: yes or no

Another discussion topic is methods of prevention and treatment in accordance with clinical guidelines adopted in different countries. Lyudmila Karan also gave an overview of different approaches.

Domestic recommendations call to take into account the fact of tick sucking and the borrelia detected in it, as well as the level of tick infection in the territory, the patient's age and some other factors - all this together makes it possible to decide whether to prescribe antibiotic therapy. Emergency antibiotic prophylaxis is prescribed during the incubation period, when it is established that the tick has been infected with borrelia. At the same time, the efficiency of using different antibiotics is approximately the same and rather high (97-98%).

At the same time, in the USA, the basis for antibiotic therapy is the very fact of tick sucking, without examining it. Evidence from an experimental study of infection suggests that 20 days of prophylactic antibiotic treatment is effective in preventing the onset of Lyme disease after tick suction, especially if started within 48 hours. And there is no need for a molecular biological or microscopic examination of the tick.

In Europe, it is strictly the opposite: antibacterial drugs are not recommended either when a tick is sucked, or even when borrelia is found in it.

First signs and long-term consequences

The incubation period for borreliosis can last up to two months. The onset of the disease in half of the cases of the disease is latent. It is impossible to diagnose them without laboratory methods. But there are also pronounced forms, and here with amim it is important for patients not to miss the moment of illness.

The first symptoms are similar to those of a common cold. One of the more common symptoms is itching at the site of the bite. Then erythema migrans (a clear hyperemic red ring, lighter in the middle) with a diameter of up to 10 cm appears. The skin in this place becomes dense and resembles an orange peel. Erythema may not appear immediately - after three or thirty days. In the second stage, new ring spots may appear on the skin. Meningitis often develops. The third stage (chronic) - large joints, often knee joints, are affected. At the same stage, encephalopathy and even encephalitis can develop. If at this time the appropriate treatment is not started or the disease is treated incorrectly, the disease gradually develops and acquires a chronic course - it proceeds as rheumatoid arthritis.

The effectiveness of treatment of the early stage of borreliosis is assessed after 6-12 months, since late manifestations of the disease can develop within a year after treatment of erythema migrans. And in general, dispensary observation should be carried out for at least two years. In about 10% of cases, even timely and adequate treatment may be ineffective. And then the disease takes on a severe recurrent or chronic form.

Rescue of the drowning

From the first warm days, the infestation of ticks turns into a huge problem not only for rural residents, fishermen and tourists, but also for the inhabitants of megalopolises who are drawn to city parks and squares. Last year, in the metropolitan region alone, about a thousand cases of infection with borreliosis were recorded. The serious consequences of encountering ticks can be avoided by following simple rules of protection against dangerous parasites.

1. You can meet a tick not only “in nature”, almost all green areas of the city are dangerous. Ticks live in wherever there is plant litter - even in a garden bed. Ticks "wake up" when the air temperature reaches 5-7 ° C, and reach the greatest activity at 18-20 ° C and humidity over 80%. Therefore, the largest number of bites occurs in May-June and August-September. If summers are hot and dry, the number of ticks decreases slightly, but they are still there.

2. The tick saliva contains anesthetic components, so its bite often remains invisible. In search of a place for suction - warm, with thin skin and good blood circulation, the tick runs from the feet to the head of an adult in an average of 15 minutes. That is why, as another preventive measure, experts recommend mushroom pickers and tourists to examine each other every 15-20 minutes.

3. Correct clothing can protect you from a bite - covering the body as much as possible, but not creating a greenhouse effect (the warmer you are, the more attractive to ticks). Special drugs that repel or kill ticks also help. Tick repellents are applied to the skin, while acaricidal agents are applied to clothing.

4. The first thing to do after finding a tick is to remove it (on your own or by contacting an emergency room) and take it to the laboratory for research. The main thing when pulling out a tick is to preserve its integrity - not to crush, not to break. Otherwise, it will be contained in its tissues and fluids, since it will be easier for pathogens to enter the bloodstream through the bite wound. It is not worth squeezing blood out of the wound for the same reasons. In addition, when examining a damaged tick, the results may be unreliable.

5. Depending on the causative agent of the infection, the incubation period after a tick bite can reach 1-4 weeks. However, when the first symptoms appear, the treatment will already be much longer than preventive therapy. That is why it is necessary as soon as possible to refer the tick itself to the study. In addition, a single tick can carry many diseases. It is always much more difficult to diagnose combined infections in humans due to vague symptoms. That is why fast and accurate diagnosis of the parasite itself is so important.