Brief overview
- What is Lyme disease? Bacterial infection transmitted by tick bites, usually in the warm season. Incubation period: Days to weeks and months pass from the bite to the onset of the first symptoms
- Distribution: Throughout forested and plant-populated Europe and North America.
- Symptoms: extensive, often roundish reddening of the skin (migratory redness), flu-like symptoms with headache, pain in the limbs, fever; paraesthesia, paralysis, nerve pain in neuroborreliosis; inflammation of the joints (Lyme arthritis); inflammation of the heart muscle (Lyme carditis).
- Diagnosis: Detection via blood and/or cerebrospinal fluid (CSF) examinations; less frequently, samples from the joint and skin.
- Treatment: with antibiotics for several weeks
- Prevention: Skin inspection after all outdoor activities, early and professional removal of the tick.
Lyme disease: description
Lyme disease is caused by motile, helical bacteria: the Borrelia bacteria. They infect humans and other mammals. Blood-sucking insects serve as carriers. The bacteria can only enter the skin of other living creatures through the bites of these parasites.
In our country, Lyme disease is transmitted in the vast majority of cases by a tick bite (not tick bite), namely by the bite of the common wood tick (Ixodes ricinus). Occasionally, organisms are also infected by other bloodsuckers such as horseflies, mosquitoes or fleas. There is no direct infection from person to person.
The most common Borrelia disease in humans is Lyme borreliosis. It occurs almost worldwide in the temperate climate zones and thus also in our latitudes. In the tropics and subtropics, other forms of Borrelia disease are also common, such as louse or tick-borne relapsing fever. It is rarely brought by travelers or refugees.
Lyme disease
Lyme borreliosis (also called Lyme disease) is the most common tick-borne disease in Europe. It is caused by certain closely related Borrelia bacteria, all of which belong to the Borrelia burgdorferi sensu lato (Bbsl) species complex.
How many ticks in an area are infected with Lyme disease pathogens varies greatly over small areas – the infestation rate varies between five and 35 percent. And not always when an infected tick bites a person does it transmit Borrelia. Even after transmission, only a small proportion of those infected actually contract Lyme disease (a good one percent).
The prognosis for patients depends to a large extent on rapid treatment: Lyme disease detected and treated at an early stage usually heals completely. Under certain circumstances, however, the disease can lead to serious complications, secondary diseases and late complications.
Lyme borreliosis: incidence
There are no typical Lyme disease areas, as is known, for example, from TBE (early summer meningoencephalitis). Lyme disease occurs in all forested and plant-covered areas in Europe and North America.
Since ticks cause Lyme disease in humans, there is a seasonal accumulation of the disease – ticks are dependent on warm weather (the common wood tick becomes active at about 6°C). In this country, Lyme disease can therefore be contracted between April and October (or earlier or later in the year if the weather is warm). Most infections occur in the summer months.
Lyme borreliosis: incubation period
As a rule, days to weeks pass between the tick bite and the appearance of the first symptoms of Lyme disease. The incubation period is the time between infection and onset of the disease.
About half of those who contract the disease develop a typical reddening of the skin called wandering redness, medically known as erythema migrans. The incubation period averages seven to ten days. In infected persons who do not develop migratory redness, the disease often becomes noticeable only weeks after infection with general symptoms of illness such as fatigue, swollen lymph nodes and mild fever.
In addition, there are patients who only show signs of organ infestation weeks to months, sometimes even years, after infection. These include skin changes (acrodermatitis chronica atrophicans) or painful joint inflammation (Lyme arthritis).
Lyme disease signs of the nervous system (neuroborreliosis) or the heart (Lyme carditis) also usually do not appear until several weeks after the infectious tick bite.
Because the incubation period for Lyme disease can also be quite long, some patients can no longer remember the tick bite. Often this was not even noticed.
Lyme disease: symptoms
Lyme disease can manifest itself in many ways. Many people with Lyme disease do not show any symptoms at first. In others, a reddening of the skin develops at the site of the bite and slowly increases in size. Doctors refer to this as erythema migrans, or wandering redness. This can be accompanied by flu-like symptoms, such as headaches, aching limbs and fever.
After a tick bite, the Borrelia bacteria spread in the tissue. Under certain circumstances, they then spread throughout the body via the blood and thus infect various organs. In this way, reddening of the skin also occurs elsewhere.
In some cases, the infection spreads to the nervous system. Neuroborreliosis then develops (see below). More rarely, the Borrelia bacteria infect other body organs such as the heart.
Late effects include chronically inflamed, painful and swollen joints (Lyme arthritis) or progressive skin changes (acrodermatitis chronica atrophicans).
You can read more about the typical signs of Lyme disease and possible late effects in the article Lyme disease – symptoms.
Neuroborreliosis
Neuroborreliosis develops when the Borrelia bacteria affect the nervous system. Often the nerve roots of the spinal cord become inflamed (radiculitis), causing excruciating, burning nerve pain. They are most noticeable at night.
In addition, neuroborreliosis can be accompanied by flaccid paralysis (for example in the face) and neurological deficits (sensory disturbances in the skin). Children in particular often also contract meningitis.
Neuroborreliosis is usually curable. In severe cases, however, damage may remain. Very rarely, neuroborreliosis progresses chronically, with the central nervous system (brain, spinal cord) typically becoming inflamed. Affected persons increasingly suffer from gait and bladder disorders.
You can read everything important about symptoms, diagnosis and treatment of neuroborreliosis in the article Neuroborreliosis.
Lyme disease: causes and risk factors
The pathogens of Lyme borreliosis are bacteria from the species group Borrelia burgdorferi sensu lato. Ticks transmit these borrelia to humans. There is no direct infection from person to person. Therefore, no human with Lyme disease is contagious! Or to put it another way: people with the disease are not contagious!
Ticks transmit Lyme disease pathogens
The older a tick is, the higher the risk that it carries Lyme disease pathogens. This is because the tick must first infect itself with the bacteria: it becomes infected with small rodents and other forest dwellers that carry the Borrelia bacteria. The bacteria do not make the tick itself sick, but survive in its gastrointestinal tract.
Ticks live especially on grasses, leaves as well as in bushes. From there, it can latch onto passing humans (or an animal) in a flash. To suck blood, it then migrates to warm, moist and dark places on the body. The armpits and the pubic region are particularly popular, for example. However, ticks can also attach themselves to any other part of the body.
Is the Lyme disease infection immediate?
While a tick is sucking blood from a human, it can transmit the borrelia bacteria. However, this does not happen immediately, but only after several hours of sucking. The Borrelia bacteria are located in the intestine of the tick. As soon as the tick starts sucking, the bacteria migrate into the salivary glands of the tick and then enter the body of the bitten person with the saliva.
It cannot be said with certainty how long a tick must suck at least for a Lyme disease infection to be likely. The probability of transmission also depends on the type of borrelia. In general, it is thought that the risk of Lyme disease is low if an infected tick has sucked on a human for less than 24 hours. If the blood meal lasts longer, the risk of Lyme disease transmission increases.
Lyme disease: examinations and diagnosis
Tick bite – yes or no? The answer to this question is an important clue for the doctor. However, since the first symptoms of Lyme disease often do not appear until weeks or months after the infection, many patients do not remember the tick bite or did not even notice it in the first place. However, they can then at least tell the doctor whether there was a chance of this happening: Anyone who often goes for walks in forests or meadows, for example, or weeds in the garden, can easily catch a tick.
In addition to the possibility of a tick bite, the doctor is also interested in the patient’s exact symptoms: In early stages of the disease, the migratory redness is particularly informative. The doctor should also be informed about general symptoms such as headaches and aching limbs. In later stages of the disease, patients often report persistent joint pain or nerve pain.
The suspicion of Lyme disease can finally be confirmed by laboratory tests. The physician can, for example, look for antibodies against Borrelia in a blood or nerve fluid sample (in the case of neuroborreliosis). However, the interpretation of such laboratory results is not always easy.
Read more about the diagnosis of Lyme disease in the article Lyme disease – test.
Lyme disease: treatment
Borrelia, like other bacteria, can be combated with antibiotics. The type, dose and duration of use of the drugs depend primarily on the stage of the Lyme disease and the age of the patient. For example, adults in the early stages of the disease are usually given tablets containing the active ingredient doxycycline. In children under the age of nine (i.e. before enamel formation is complete) and pregnant women, on the other hand, this antibiotic may not be used. Instead, the doctor prescribes amoxicillin, for example.
In later stages of the disease (chronic neuroborreliosis, etc.), doctors often also use antibiotics such as ceftriaxone or cefotaxime. The drugs are usually administered as tablets, but sometimes also as an infusion via the vein (e.g. ceftriaxone).
The success of antibiotic therapy depends particularly on the start of treatment: In the early stages of Lyme disease, treatment is usually more effective than in later stages.
Read more about the treatment of Lyme disease in the article Lyme disease – therapy.
Lyme disease: course of the disease and prognosis
The rapid start of therapy is very important in Lyme disease. The course and prognosis of the disease are significantly influenced by whether the bacteria have had time to spread and multiply in the body. With the right treatment, the symptoms usually disappear completely.
In some circumstances, however, Lyme disease signs persist. Sometimes patients retain mild facial nerve palsies for life. Other sufferers have dragging joint pain. A reaction of the immune system that lasts beyond the infection causes inflammation here.
Early signs are often missing or remain unnoticed, which is why Lyme disease is then detected and treated later. The treatment of Lyme disease in such advanced stages of the disease is always difficult. Sometimes it requires further administration of antibiotics.
Months of antibiotic therapy, multiple repetitions or combinations of multiple agents are not recommended by the experts of the medical guidelines!
In some cases, people become infected without subsequently developing clear signs of illness. In them, antibodies against Borrelia can be detected without any previous illness. The infection therefore heals independently and with the help of the immune system.
However, once Lyme disease has been overcome and healed spontaneously or with therapy, it does not provide immunity. This means that one can later become newly infected with Lyme disease and contract it.
Post Lyme disease syndrome
Post-Borreliosis syndrome is particularly popular in health magazines or the media. However, there is no clear definition that describes this clinical picture. The media report patients who complain of muscle pain, fatigue, lack of drive or concentration problems, for example.
However, studies to date indicate that these non-specific complaints do not occur more frequently than is generally the case in people who have been through a Borrelia infection. Therefore, many experts doubt that the supposed “post-Borreliosis syndrome” is actually related to Lyme disease.
Known late effects of a Borrelia infection are persistent skin changes (acrodermatitis chronica atrophicans), joint inflammation (Lyme arthritis) or neurological symptoms (chronic or late neuroborreliosis).
If affected persons suffer from post-Borreliosis syndrome signs, it is advisable to clarify other possible causes of these symptoms. For example, the reason for chronic fatigue or poor concentration may be a viral infection or even a hidden depression. Then the doctor can initiate a suitable treatment.
Lyme disease & pregnancy
Earlier case reports and small studies initially suggested that Borrelia infection during pregnancy disrupted fetal development. However, more recent studies have not yet confirmed this assumption.
Nevertheless, there is no evidence that excludes the harmful effects of an infection during pregnancy beyond doubt. For this reason, the doctor also consistently treats Lyme disease during pregnancy with antibiotics. For this purpose, he chooses active substances that do not harm the mother or the unborn child.
According to current knowledge, women who have already had Lyme disease and were treated appropriately before becoming pregnant need not worry.
In addition, there is no evidence that mothers can transmit Lyme disease through breastfeeding.
Lyme disease: prevention
The only starting point for protection against Lyme disease are ticks: Prevent tick bites or remove an already sucking tick as soon as possible. The following tips apply:
When you are out in the woods and meadows or doing gardening, you should wear light-colored (white) clothing if possible. Ticks are easier to spot on these than on dark textiles. The arms and legs should also be covered by clothing, so that the small bloodsuckers do not find skin contact so easily.
You can also apply tick or insect repellents. However, keep in mind that these do not provide 100% protection against a tick bite and are only effective for a few hours.
Avoid shortcuts through tall grass and bushes. Instead, stay on paved paths.
In any case, you should thoroughly check your entire body for ticks after spending time in the great outdoors. Also check your pets for possible ticks: The parasites could pass from your cat or dog to you.
If you find a sucking tick on your skin, you should remove it immediately and professionally: Grasp the tick with fine tweezers or tick forceps directly above the skin and pull it out slowly and without twisting. While doing so, press as little as possible to avoid squeezing body fluids of the animal into the wound. Also check that you have not accidentally torn off the body while the head of the parasite is still in the wound.
If you try to poison or suffocate a tick sucking on your skin with oil or other substances, you increase the risk of infection! Because in the struggle for survival, the tick may transmit even more Borrelia.
You should then disinfect the puncture wound. This does not protect against Lyme disease, but prevents wound infection.
Taking antibiotics as a precaution after a tick bite (without a diagnosis of Lyme disease infection) is not recommended.
There is no Lyme disease vaccination!
Doctors can vaccinate against early summer meningoencephalitis (TBE), which is also transmitted by ticks. It is particularly advisable for those who live in or travel to risk areas. However, there is no preventive vaccine against Lyme disease.
