Many open questions in Lyme disease by ticks

Spread of Lyme disease by ticks is a growing problem

22/04/2012

Every year, doctors, health authorities and associations warn of the health risks that a tick bite can bring at the beginning of the tick season. Because the tiny bloodsuckers often serve as transmitters of dangerous pathogens, which can cause, for example, Lyme disease or an early-summer meningoencephalitis (TBE).

At yesterday's kick-off of the Annual Meeting of the German Borreliosis Society (DBG) 2012, the speakers emphasized the medical challenges resulting from the increasing spread of Lyme disease by ticks. Although the infectious disease has long been known to bring the diagnosis and treatment often still considerable difficulties. According to the chairman of the German Borreliosis Society, Kurt E. Müller, "significant progress has been made in recent years, but reliable therapy remains a major problem."

Lyme disease and TBE
With the mild spring temperature, the tick season has begun. From seven degrees Celsius, the little bloodsuckers get active and start their search for food. Here human blood is just as gladly taken as birds, domestic animals and wild animals. The tiny creatures attach, pierce the skin and begin to suck blood. In the course of feeding, the ticks swell to many times their actual body size and fall off when they are full, by themselves. This process in itself would not be a particular problem for the human organism, but the tiny bloodsuckers often transmit pathogens into the wound. Among the most common pathogens that can be transmitted by a tick bite, include the Borrelia bacteria, which cause so-called Lyme disease in humans. The ticks also frequently pass on TBE viruses during the sucking process, which can lead to flu-like symptoms such as fever and headache, as well as potentially life-threatening meningitis.

Diagnosis difficulties with Lyme disease
In tick-borne borreliosis, one of the main problems is reliable diagnosis as early as possible. Although the so-called Wanderröte, which shows up as a red, growing spot on the skin (first around the puncture site, later on other parts of the body), is a typical symptom. But about one third of the patients do not suffer from this conspicuous disease feature, report the experts of the DBG. The other symptoms such as fever, muscle, joint and limb pain are also so unspecific that the suspicion often does not fall on a Lyme disease. Thus, the pathogens often spread over weeks in the body of those affected, before even a study for Lyme disease takes place. If a medical examination is carried out, then it is not always ensured that the pathogens are discovered. "The diagnosis is not made with sufficient certainty. Findings are often interpreted differently and it is not often assessed differently when a Lyme disease requiring treatment exists, "said DBG Chairman Kurt E. Müller. To ensure that the detection of an existing Lyme disease succeed, researchers from Innsbruck have therefore developed a method in which tissue samples using a special cutting technique can be systematically spirally searched through the microscope, reported Müller. Through this so-called focus floating microscopy "we can find Borrelia easier and recognize the need for treatment more reliable," said the expert.

Difficult treatment of Lyme disease
If a Lyme bite is diagnosed after a tick bite, treatment with antibiotics usually begins immediately. Especially with early detection of the pathogens, the chances of a cure are quite good. But again and again, the doctors push their limits. The antibiotics do not work in the desired form and there is a threat of chronic Lyme disease with sequelae such as inflammation of the joints, the heart muscle or the nervous system. According to the DBG chairman, the difficulties in the treatment also arise from the ability of the pathogens to "change their structure and, moreover, to retire into a form of rest." Reliable treatment would thus be made considerably more difficult, Müller explained. Also, in the opinion of the expert, the individual constitution of patients plays an essential role in the treatment and should therefore be considered. "We have to deal even more with the personal characteristics," explained Müller at the DBG Annual Meeting. The individual power of the immune system should be recorded and, if necessary, measures that strengthen the immune system should be included in the therapy, the expert said.

Up to 400,000 new cases of Lyme disease per year?
How many people actually suffer from Lyme disease in Germany every year after a tick bite, according to Kurt E. Müller is unclear. To the infectiousness and disease numbers give it "extremely contradictory numbers, because no uniform registration exists", so the DBG chairman further. For example, the National Reference Center for Borrelia in Erlangen assumes that between 60,000 and 100,000 people in Germany are diagnosed with Lyme disease every year. According to Müller, however, there are also "numbers that indicate that around 0.5 percent of the population is newly diagnosed with Lyme disease every year" - which would be around 400,000 people per year in Germany. The areas in which particularly many ticks carry Borrelia are Baden-Württemberg and Bavaria, which are classified as high-risk areas in Germany. Overall, however, the spread of the pathogens in the ticks population is increasing throughout Germany, according to Kurt E. Müller. The associated health risks to the population would still underestimated today, stressed the expert.

Registration for Lyme Disease
Some federal states have introduced a reporting obligation to monitor the spread of Lyme disease, although according to the DBG chairman, the data collected has so far only been of limited use. Although in the East German states and Rhineland-Palatinate already a mandatory reporting and in Bavaria, the introduction is planned, but "it would have been better to wait and agree on a standardization of the reporting criteria," said Kurt E. Müller. In the current reporting procedures "the numbers are questioned again and again," complained the expert. The identification of risk areas is advantageous in that the population is sensitized to the risk of Lyme disease transmission after a tick bite in appropriate regions. Also, people may take appropriate protective measures when staying outdoors to minimize the risk of tick bites.

Body-covering clothing, tight cuffs and high shoes are appropriate here. After a stay in nature, the body should be thoroughly searched for ticks. Possibly adherent animals should be removed promptly with a small pair of tweezers or tweezers, avoiding bruising of the ticks so that they do not secrete their gastric contents into the puncture wound. The tendency is that the earlier the ticks are removed, the lower the risk of transmission of TBE or Lyme disease. (Fp)

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