Diseases caused by ticksTicks can transmit a variety of diseases and therefore pose a danger to young and old alike. Especially people who spend a lot of time in nature have an increased risk of being bitten by a tick.
Which diseases are transmitted by ticks?
Tick-borne encephalitis (TBE) is a viral disease that can lead to inflammation of the brain, meninges and/or central nervous system. About 30-40% of infected persons actually become ill. Duration from tick bite to onset of disease (incubation period) varies from a few days to a month. The disease typically progresses in 2 phases: in the first phase, flu-like symptoms occur, such as fever, headache and aching limbs. With ca. in one third, after a symptom-free interval of about one week, the second phase occurs, in which the disease spreads to the central nervous system.
Depending on the involvement of the individual parts of the brain and nerves, 3 forms of the disease can be distinguished in principle:
1. Meningitis (inflammation of the brain) 2. Involvement of the meninges and brain (meningoencephalitis) 3. additional involvement of the spinal cord (myelitis)
Depending on the severity of the disease, there are corresponding symptoms: severe headache, high fever up to over 40 degrees, neck stiffness, confusion and/or impaired consciousness. There may also be paralysis, gait disturbances, seizures and/or respiratory disorders. Although severe symptoms of the disease usually disappear within 1-3 weeks, convalescence can take a very long time – long hospital stays, limited ability to work and a considerable impairment of the quality of life are often the result (also called post-encephalitic syndrome). Even in the case of a milder course of the disease, there can be z.B. personality changes and/or lack of concentration.
Important: Once the disease has broken out, there is no causal treatment possibility. Only the symptoms can be alleviated.
Lyme disease is caused by bacteria – so-called "Borrelia". It is the most common tick-borne disease in Austria. The pathogens live in the intestine of the tick and therefore it takes a while (probably a few hours) for the borrelia to enter the blood of the host after a bite. The faster the tick is removed, the lower the risk of transmission and disease. The disease is divided into 3 stages, whereby not all stages occur in all patients and atypical courses are often observed.
In the early stages, after an incubation period of a few days to three weeks, flu-like symptoms are predominant, such as z.B. Fatigue, fever and headache, which are also present in many other diseases. This makes it difficult to detect Lyme disease. The only clear indication is a circular rash around the injection site, which can migrate (the so-called "rash"). "wandering redness"). This redness may disappear without treatment, but the infection may continue to progress. Unfortunately, this rash only appears in ca. 50% of those affected, d.h. one can also be infected with Borrelia without this indication.
In stage 2, the large joints, the musculoskeletal system and, more rarely, the heart are affected weeks to months after infection. Of particular importance is also the infestation of the central nervous system with the different, difficult to diagnose clinical pictures.
The late stage is rarely observed, after months to years, and is characterized by inflammation of the joints and diseases of the nervous system. Therefore, in case of symptoms that cannot be explained, one should also think of Lyme disease. The disease can be effectively treated with antibiotics. Usually heals without consequences if treated in time. A preventive vaccine against it does not exist yet. The "tick vaccination" therefore protects against TBE, but not against Lyme disease!
Other tick-borne diseases
In addition to TBE and Lyme disease, ticks are carriers of many other pathogens and can therefore also transmit other diseases. The majority of these diseases do not occur in our latitudes. These include z.B.:
The disease, which is relatively rare in humans, occurs mainly in Mediterranean regions. Fever, fatigue and muscle pain are the hallmarks of babesiosis. This infection occurs far more frequently in animals and is similar to human malaria, which is why it is also referred to as "dog malaria".
Spotted fever (rickettsialpox)
In Europe, the "Mediterranean spotted fever" is best known. The disease is also called rickettsialpox, after the name of the bacteria that are associated with the parasites. Typical symptoms are a high fever that lasts for days, and a fever that begins on 4.-7. Skin rash (exanthema) occurring during the day.
Crimean-Congo fever has been reported in southeastern Europe, Asia, and Africa. The disease is caused by the virus CCHFV (Crimean-Congo Haemorrhagic Fever Virus). Ticks nest in the fur of sheep, goats, cows, rabbits or camels and ingest the virus with the blood of the infected animals. Transmission to humans occurs via the tick bite or. by direct contact with the infected animal. The virus disrupts blood clotting, resulting in intestinal bleeding, hematemesis and internal bleeding. One in two infected persons who develop the fever dies. There is no vaccination protection yet.