Tick-borne encephalitis is often called “the spring-summer encephalitis.” As soon as the sun starts to warm the earth and the first buds bloom, ticks wake up after hibernation. And although the incidence usually peaks in May, the risk of infection persists from spring to autumn. It is a big mistake to believe that ticks attack only outside the city. One can become a victim of encephalitis very near to home - in a nearby park or square, ticks can get into the house along with branches brought from the woods or “ride” on pet hair.
What is tick-borne encephalitis?
Tick-borne encephalitis is an acute viral infectious disease. The virus can exist for a long time in the body of the tick without causing harm to its carrier and it can be transmitted from one generation of ticks to the next. It can be transmitted to a human only via a tick bite.
Foci of tick-borne encephalitis virus were found in Austria, Czech Republic, Germany, Poland, Finland, and in the Baltic countries. More than 80% of cases were ordinary citizens and tourists who have visited the parks, gardens, were walking in the woods and did not know about the danger.
Infection and the course of disease
After a bite the virus enters the blood and the nervous system. The time between the bite and the onset of symptoms varies from 1 day to a month (10 days on average). The first symptoms of illness are fever (up to 38-39 degrees C), severe headache, sometimes nausea, vomiting, joint pain, weakness, feeling jaded, sleep disturbances, cough and runny nose. In some cases, the disease can end at this stage and the person recovers. But in more severe cases, 3-5 days after the bite, lesions of the central nervous system are beginning to develop - Meningitis (inflammation of the lining of the brain), encephalitis (inflammation of the medullary substance), meningoencephalitis (inflammation of the medullary substance and the lining of the brain).
There is no specific treatment of encephalitis. For therapy, they use immunoglobulin, which contains ready-made antibodies against the virus of tick-borne encephalitis, antiviral agents, as well as drugs, which help to get rid of the symptoms.
Prevention of tick-borne encephalitis
In order to prevent tick-borne encephalitis a course that consists of 2 vaccinations is carried out with an interval of 1-3 months. There is also a quick vaccination with an interval of 14 days. Repeated vaccination against tick-borne encephalitis is carried out after 9-12 months and 3 years.
Modern vaccines contain inactivated (killed) virus of encephalitis. There is no live virus in the vaccine, but the antigenic structure of viral particles is preserved. After the introduction of the vaccine, the immune system recognizes viral antigens and begins to produce antibodies. Natural antibodies directly block the development of the virus that has entered the body. Several doses of vaccine are required in order to maintain a long-term defense reaction. The effectiveness of the vaccine can be assessed by the concentration of protective antibodies in the blood (IgG against the virus of tick-borne encephalitis). Protection against tick-borne encephalitis appears no earlier than two weeks after the second dose of vaccine.
Vaccination is an effective method of protection. At one time Austria was in the lead in Europe on the incidence of tick-borne encephalitis. Nowadays more than 80% of the population of Austria is vaccinated. The effectiveness of the vaccine is more than 95%. This means that vaccination could prevent at least 95 out of 100 cases of the disease.
What is immunoglobulin for the “quick vaccination?”
What is it used for?
If you urgently need to go to the countryside, and waiting for 2 weeks is not an option, there is a possibility to make an urgent prophylaxis with immunoglobulin. In this case, the protective effect occurs within a day, but it remains no longer than 1 month. One should not exaggerate the effectiveness of such measures. The protective effect of immunoglobulin is much weaker.
Immunoglobulin is also used for emergency treatment (i.e., urgent prophylaxis after tick bite). So if shortly after the tick bite, you happen to come to a population aggregate, it makes sense to turn to a medical facility for the introduction of immunoglobulin.