Translated material
Bite-clan
Encephalitic ticks killed 54 people in Russia last year
Over the past year, the incidence of tick-borne viral encephalitis in Russia has increased by 33%. During the epidemiological season of 2009, more than 400,000 adults and 110,000 children turned to doctors after being bitten by ticks. Encephalitis...
Over the past year, the incidence of tick-borne viral encephalitis in Russia has increased by 33%. During the epidemiological season of 2009, more than 400,000 adults and 110,000 children turned to doctors after being bitten by ticks. Encephalitis infected almost four thousand people, including 444 children. In 54 cases, the disease ended in death.
Meanwhile, viral encephalitis is by far the most serious, but far from the only disease carried by these insects. There are individuals - carriers of tick-borne borreliosis (Lyme disease), tick-borne typhus, hemorrhagic fever, tularemia, ehrlichiosis. The number of people infected with these diseases with names less familiar to our ears is also growing. The reason for this is the increase in the activity of the natural habitats of ticks, including their ixodid (disease-carrying) counterparts. The area of distribution of these insects in the Moscow region has significantly expanded - although not a single case of the disease has yet been recorded in the region, infected ticks have been found in almost all administrative districts. If we talk about Russia as a whole, encephalitis ticks are found in 46 regions of the country.
Experts attribute the increase in the number of these insects to the reduction of anti-tick treatments and the ineffectiveness of the drugs that are used in this case. The list of cultivated areas, as a rule, includes sanatoriums and children's health camps, and almost never - parks, forest areas in urban areas and gardening associations.
Tick-borne encephalitis is a serious and severe disease. As a rule, the disease begins to manifest itself in the second week after the bite. At first, it behaves almost like the flu - general weakness, chills and high fever (it all depends on the virulence of the virus and the general condition of the whole organism), but it is not uncommon for encephalitis to complete its destructive work. Then, at best, the patient's meninges will be affected, which will manifest itself in an even higher temperature, severe headache, vomiting and photophobia. At worst, the virus will directly affect the brain cells, which will be accompanied by impaired consciousness, mental disorders, convulsions, paresis and paralysis. It is with this course of the disease that the risk of death is highest.
An effective antiviral treatment for tick-borne encephalitis does not yet exist. Therefore, the most effective way to protect yourself is to get vaccinated.
The principle of vaccination is simple. A vaccine is introduced into the human body - a biological preparation, the main part of which is particles of an infectious agent, that is, a weakened or killed pathogen of a particular disease or part of it. Since the virus is weakened when it enters the bloodstream, it cannot multiply and cause disease, however, lymphocytes recognize strangers and antibodies begin to be produced in the body. In the case of encephalitis, antibodies to this virus remain in the blood for up to several years. And therefore, when a “wild” infection enters a previously vaccinated organism, it no longer needs time to produce antibodies. As a result, a vaccinated person, even if bitten by an encephalitic tick, does not get sick at all or the disease proceeds in a very mild form.
Despite the obvious benefits of vaccination, many still believe that getting vaccinated exposes oneself to an unreasonably high risk. Of course, any intervention, even taking aspirin, is always a certain risk. In their early days, vaccines were indeed often unsafe. In recent decades, the situation has changed dramatically.
To date, two types of domestic vaccines against tick-borne encephalitis are most common in Russia - dry, produced by the Institute. Chumakov, and liquid "EnceVir", produced by the state company "Microgen". The first has been for many years, and it is mainly purchased for the army, the second is much younger, and it is this that is purchased by 80-90% of the endemic regions of the country.
Nevertheless, the introduction of a vaccine is the introduction into the body of a virus, albeit weakened, but still. Therefore, side effects are inevitable. At first, the injection site may become red and swollen, and the lymph nodes may swell. In the first two days, the temperature may rise to 38 degrees, accompanied by malaise, muscle and joint pain, such reactions develop in 9-10% of those vaccinated and disappear within three days.
However, allergic reactions that can occur immediately after administration are many times more dangerous. They manifest themselves within the first 30-45 minutes. In this case, the qualifications of medical personnel are especially important, who, regardless of the presence of an allergic reaction, must leave the vaccinated under supervision for at least half an hour after administration.
Seasonal vaccination-2010 started in early spring - the tick wakes up in April, and to develop stable immunity, you need to do at least two vaccinations a month apart. However, in early March, vaccination in the Chelyabinsk region - one of the most infected with ixodid ticks - was suspended. Several schoolchildren had a headache and a high temperature after the vaccination, they were hospitalized, but the next day all the children felt well. Despite the fact that fever is a common occurrence during vaccination, and complications are allowed in 7% of those vaccinated (in the case of Chelyabinsk schoolchildren, about 1% of those vaccinated reacted sharply to the vaccine), specialists from the regional Rospotrebnadzor ordered to suspend the distribution of EnceVir, which schoolchildren were vaccinated with. “The ban does not even concern the vaccine itself, but its batch of three series,” explains Raisa Kosareva, head of the epidemiological surveillance department of the department. - They were withdrawn from sale and sent for examination to the manufacturer of the Federal State Unitary Enterprise "MPO Microgen", in Tomsk, as well as to the L. A. Tarasevich State Research Institute for Standardization and Control of Medical Biological Preparations. An expert commission from the Tarasevich Institute, having visited the manufacturing plant last week, has already issued a preliminary conclusion: no violations were found either in the technological process or in the quality of the manufactured drug. However, the final conclusion will be announced only in May.
The current situation is reminiscent of the story of 2006 with the domestic flu vaccine "Grippol" - then cases of allergic reactions to the vaccine were also widely discussed, but it soon became clear that the real percentage of complications was negligible, and most of them arose due to the illiterate actions of medical workers who were vaccinated. The situation with Grippol was more like a competitive struggle than concern for people's health: about 22 million people were vaccinated with this vaccine every year for more than ten years, and this is a tasty morsel for competitors. Perhaps the noise around the complications after "EnceVir" is rising for the same reason?
A comment
Vladimir Zlobin , academician of the Russian Academy of Medical Sciences, professor :
- Vaccination really seriously affects the number of people infected. In order for the incidence to decrease sharply and remain at a low level, mass vaccination of the population of highly endemic areas is necessary. In Austria, more than 90% of the population has been vaccinated, after which the incidence has fallen from 800 cases per year to 40-50 and remains at this level. Mostly unvaccinated people get sick. All authors note that if a vaccinated person still develops a disease after being bitten by an infected tick, then it proceeds in a mild form.
It is difficult to expect from any vaccine to be absolutely areactogenic, i.e. does not cause allergic reactions.
Possible side effects are always spelled out in the instructions for vaccines. They should be limited to everything.
However, side effects are more common in children. Hence the desire of manufacturers to create "children's vaccines."
As for vaccines against encephalitis, "children's vaccines" are already being produced abroad and approved for use in the Russian Federation. These vaccines contain half the dose of viral antigen. At present, "children's vaccines" have been created in our country, and after their certification, they will probably appear in practice. If all vaccine parameters are met, there is no risk.
PS In 2009, only 7.7% of those who suffered from tick bites and applied to medical institutions were vaccinated against tick-borne encephalitis.