Tick-borne encephalitis: a neglected danger
Perhaps everyone has heard of tick-borne encephalitis, but even today you can hear a lot of myths regarding this disease. So, for example, in Siberia people buy mass insurance against a tick bite, which includes an injection of immunoglobulin; use drugs such as iodantipyrine or anaferon; in the end, they decide that it’s simple enough to get a tick and cauterize a bite.
This article is not a guide to the prevention and treatment of tick-borne encephalitis. In the event that you are bitten by a tick, you must first consult a doctor .
Most of the material presented below can be found on the blog of the doctor and the popularizer of medicine Alexei Yakovlev (whose work served as the inspiration for this article).
The most important for us are three species of ticks of the ixodidae family: meadow, dog and taiga. A meadow tick prefers animals, but can also attack humans. However, the most important for us is the dog (forest) and taiga ticks.
Image of Lancet, 2008
Ticks do not jump on people from high branches - basically they sit in the grass at a low height, not more than half a meter. However, they can easily get over their clothes on their heads - the chance to find a tick in the hairdo is very high.
Ticks are carriers of many infectious diseases, including:
- Lyme disease (tick-borne borreliosis) - a bacterial infection, which at the initial stage is often manifested in the form of annular erythema (annular redness) at the site of a tick bite;
- babebiosis (pyroplasmosis) - a parasitic disease;
- tick-borne rash typhus.
A meadow tick also serves as a carrier of such a rare disease as Omsk hemorrhagic fever .
Tick-borne encephalitis is a viral disease. Its causative agent is flavivirus (an RNA-containing class IV virus according to Baltimore's classification); from the same family as the hepatitis C virus. This virus is neurotropic, that is, it affects the nervous system, and the gray matter of the brain and its membrane are most affected. It can also affect the spinal cord (but not necessarily). Approximately one third of those who are ill remain with life-long neurological disorders (disability is very likely).
Tick-borne encephalitis virus has several subtypes. The dog tick carries the European subtype, the taiga tick - the heavier Siberian and Far Eastern subtypes. Mortality from the European subtype is about 1-2%, from the Far East it can exceed 20%.
Of course, before talking about the prevention of each specific disease, it is necessary to mention the prevention of tick bites themselves. To do this, there are a number of drugs:
- repellents with a high content of DETA (30%) - suitable for application to open areas of the body;
- acaricides containing permethrin (processed clothing, especially those places where the tick can crawl onto the skin).
It will not be superfluous to fill your trouser legs in socks, put your hair under the hood and trite to avoid places of accumulation of ticks.
However, what if the tick nevertheless reaches its target?
If a sucking tick is found, it should be removed immediately, without crushing it. The sooner this is done, the less likely it is to become infected; tick should be tested for the presence of tick-borne encephalitis and Lyme borreliosis by PCR .
There is the only effective method of combating tick-borne encephalitis - vaccination . There are several vaccines on the market, I personally was vaccinated with the Austrian FSME-Immun, the German Enzepur is no less effective. From Russian vaccine available FSUE them. M.P. Chumakova and the EnceVir vaccine (I have not personally encountered it, but there have been complaints about the latter because of side effects ).
Many people recall the danger of tick-borne encephalitis only in the spring, and believe that it is too late to get vaccinated at this moment. This is not true! Yes, indeed, for the main vaccination schedule, the first dose must be administered as early as the fall, but there is also an emergency schedule. The immunity formed by the emergency scheme is less stable and requires the introduction of boost for the next season. In case of vaccination, both the main and emergency regimens require revaccination every 3-5 years.
Even if a person is vaccinated against tick-borne encephalitis, this does not mean that you do not need to protect yourself from tick bites! Other diseases are also extremely dangerous.
In short, there is no cure . Despite the fact that specific immunoglobulin has been used in Russian practice for decades, there is still no convincing evidence of its effectiveness in reducing the severity of the disease, there are only suggestions  (and it is completely incapable of preventing the disease). Nevertheless, many people (especially in Siberia) prefer the so-called “tick bite insurance”, which includes the introduction of immunoglobulin, which is known to be safe and effective.
Other drugs offered as measures for the prevention and treatment of tick-borne encephalitis are ineffective at all. So, for example, anaferon is a homeopathic remedy that cannot work by definition.
For another drug, iodantipirin, its effectiveness in preventing the disease was compared using immunoglobulin  (both drugs were shown to be equally effective). Yes, indeed, to prevent the disease, the effectiveness of these drugs is the same (and equal to zero).
Brief conclusions for those who are too lazy to read all of the above
- Tick-borne encephalitis is a serious disease that can result in disability or death;
- There are many other infections that mites carry - so you should protect yourself from tick bites in general with repellents that are high in DET and acaricides containing permethrin;
- The only protection against tick-borne encephalitis is vaccination; there is no cure.
- Alexey Yakovlev’s blog, “Meet Ixodid Mites”
- Letter of Rospotrebnadzor of 05/07/2010 n 01 / 7060-10-32 “On the suspension of immunization of children with EnceVir vaccine”
- May early intervention with high dose intravenous immunoglobulin pose a potentially successful treatment for severe cases of tick-borne encephalitis?
- The results of the study of the epidemiological effectiveness of iodantipirin as a means of emergency prevention of tick-borne encephalitis