Basic Information on Lyme Disease

Lyme disease, also called Borreliosis or Lyme borreliosis, is a bacterial infection mainly transmitted by ticks. It can cause severe symptoms.

Spread

Lyme disease has been reported on all continents, but especially in the northern countries. In Europe, currently around 65,000- 100,000 Lyme disease cases are officially reported each year. It occurs especially in Germany, Austria, Switzerland and other central European countries.

The actual number, however, is much higher. The reason is that Lyme disease infection displays various symptoms that cannot easily be classified. The fact is that Lyme disease is one of the most common unrecognized or misdiagnosed infectious diseases in Europe and USA.

Figure 1: ticks transmit Borrelia pathogens, which can trigger an infection in the body.

Infection

The causative pathogen of Lyme disease is a bacterium of genus Borrelia, which belongs to the spirochetes family. Spirochetes are spindle-shaped, actively moving bacteria. They have effective methods to hide from the immune system of the body. As a result, it is possible that subsequent symptoms of the disease develop without being recognized as such.

The main transmitter of Borrelia is the tick, but other blood sucking insects (mosquitoes, horseflies, lice and fleas) can also transfer the disease. It is estimated that 5-35% of ticks are infected with Borrelia.

Ticks carry the pathogens in their digestive tract. The pathogens multiply in the intestine area and migrate from there into the salivary glands. In the case of tick bites, they flow into the bloodstream of the host (human or animal) and can thus enter the joints as well as various organs, including the skin, heart, brain and bladder. Because of their high mobility, Borrelia can move well within the body. They release nerve-damaging substances.

Course of Lyme disease

Lyme disease is manifested as an inflammatory disease that can affect many organs in the body. In its early (localized) stage it affects mainly the skin (Figure 1). In later stages, the inflammation spreads to the joints, nervous system and also to the heart, muscles and other organs. Since conventional therapies with antibiotics only have a limited effect in the late stages of the disease, Lyme disease can develop or flare up, although the patient initially shows no symptoms.

In nature, ticks go through several stages of development. They hatch as larvae from the egg, become a nymph after moulting and finally a mature tick. The tick can transmit the borreliosis bacteria in any stage of development. The nymphs are the most dangerous, especially as they are particularly numerous in spring and summer and measure around of 1-2 mm, making them difficult to detect.