What is it about ?
Ticks and bacteria
Lyme disease or Lyme borreliosis is an infection caused by the bacteria Borrelia, the most common species of which is Borrelia burgdorferi. Other species also circulate in Europe. These bacteria are transmitted by the bite of a tick.
Only ticks that are themselves infected can transmit Lyme disease. The longer the infected tick clings to you, the greater the risk of infection. But not all ticks are infected with the Borrelia bacteria, far from it. It is estimated that about 1 in 50 tick bites cause Lyme disease.
A tick is an arachnid (an animal in the spider family), which feeds on human and animal blood. Without blood, a tick cannot develop or reproduce. Ticks live in bushes, grass and trees. As soon as a suitable host presents itself, they drop and cling to the skin. They usually move around until they find the most suitable place on the body. In humans, this area is often a skin fold (like the groin). They can also get caught in the arms, legs and scalp.
Ticks are found all over the world. A number of species also live in Belgium. Only a few of them transmit pathogens such as Borrelia burgdorferi. These species are mainly active from the beginning of March to the end of October.
Course of Lyme disease
Lyme disease progresses in several phases. The first phase (or early phase) is characterized by local skin symptoms. A few days or even weeks after a tick bite, a characteristic rash appears around the lesion. This rash is usually not painful. In some cases, however, it may cause a slight itching or burning sensation. For the first few days, the area around the bite may be quite red. Usually, the redness spreads outward and the center of the rash gradually clears up to its normal color. It thus takes the form of a ring or a target. The rash can be very extensive, reaching over 8 inches in diameter. This rash is often confused with the rash surrounding the bite, which is caused by the tick’s saliva. But these disappear in a few days. The redness of the rash after a bite from an infected tick can persist for weeks, even up to a month or more. If the rash at the site of a tick bite exceeds a diameter of 5 cm and it has been more than a week since the bite, it is most likely Lyme disease. This characteristic skin symptom is also known as erythema migrans.
This early phase can sometimes be marked by the appearance of symptoms flu-like, such as tiredness, a general feeling of ill-being or a slight fever. It is also possible that there is no rash or at least not noticed. In this case, a simple ‘summer flu’ can suggest a Borrelia infection.
If the infection is not identified and treated in time, the disease may continue to spread throughout the body in a subsequent phase. About 1 in 2 times, other complaints and symptoms appear after a few weeks, months or years, possibly at the same time. These symptoms are:
- neurological symptoms (this is called ‘neuroborreliosis’): fatigue, pain in the hands, drooping mouth (due to facial nerve palsy), loss of strength in the limbs, irritation or aggressiveness, loss of appetite, loss of memory, tingling in the hands, reduced sensation in the limbs, headaches, poor vision in one eye, double vision, …
- muscle and skeletal symptoms (‘Lyme arthritis’): muscle and joint pain, joint swelling, slight increase in temperature, pain around the tendons, …
- skin symptoms: lumps, decreased sensation in some areas, slowly growing bluish swelling of the skin, usually in the arms and legs.
On the other hand, if the infection had been well treated, these symptoms are very exceptional.
What is its frequency?
The frequency of Lyme disease varies widely from country to country, and even from region to region. In areas where ticks are prevalent, up to 1,500 in 100,000 people can contract Lyme disease per year. It is important to remember, however, that not all tick bites cause Lyme disease. It is estimated that only 1 in 50 tick bites cause the disease.
How to recognize it?
It is important to know that symptoms can appear several days or even weeks after a tick bite. If you notice a red rash where you have been bitten by a tick that spreads over a few days and / or if you develop a flu-like condition a few days after being bitten by a tick, it is you may have Lyme disease.
What can you do ?
Prevention
The main measure is the prevention of tick bites. If you go for a walk in a wooded or grassy area, find out about the presence of ticks. Preferably walk in the middle of the trail (the most compacted part), when walking on wet and grassy terrain. Wear long pants, preferably a light color, to better see possible ticks. You can optionally slip the bottom of your pants into your socks, so that your legs are completely covered. Put a cap on the children. You can apply a repellant to your legs, such as DEET (however, be careful, the doses to be used are different in adults and children!). Prevention is still essential, even if you have had Lyme disease in the past. This is because the body does not develop immunity against the disease and it is therefore possible to contract it several times.
Have you been bitten by a tick?
If you have been bitten by a tick, you can easily remove it yourself as long as you observe the following rules:
- After the ride, carefully inspect your armpits, groin and scalp. If necessary, get help. It is important to remember that the tick must be removed from the first day, as the risk of infection increases over time.
- To remove the tick, preferably use a tick remover. You can buy it at the pharmacy. Do not disinfect the skin before removing the tick.
- If you don’t have a tick puller available, try removing the tick with your fingers: roll the tip of your wet finger over the tick. Avoid scratching the tick: you risk breaking off small pieces, which can remain in the skin.
- When extracting, try to grip the tick as close to the skin as possible, near the head, without pinching the back.
- Once the tick is removed, disinfect the skin with aqueous disinfectant or alcohol and note the day of the bite.
Do not hesitate to contact your doctor if the tick has remained attached to the skin for more than 24 hours. Ditto if you observe a red rash, which spreads more and more, at the site of a tick bite. To date, there is no effective vaccine against the bacteria Borrelia.
How is the diagnosis made?
The doctor will ask you a few questions and examine you. On this basis, he will be able to assess whether you are at risk of having contracted Lyme disease. It will take into account your symptoms and where you have (possibly) been bitten by a tick. It can also help you remove the tick if you haven’t done it on your own. In the presence of the characteristic rash after a tick bite, treatment is started immediately. At a later stage, your doctor may do a blood test to see if you have Lyme disease. If you have neurological symptoms, your doctor may need to do a lumbar puncture in order to analyze the cerebrospinal fluid.
What can your doctor do?
A tick bite without a characteristic red skin lesion and other symptoms of Lyme disease does not need to be treated. If Lyme disease is suspected, your doctor may prescribe antibiotics. Usually, this treatment should be taken for a long period of two to three weeks. If the disease is not diagnosed until a later stage, antibiotic treatment is also started, often for a period of three to four weeks. In some situations (in case of late initiation of treatment for neurological symptoms), antibiotics are given as an infusion. As a rule, pregnant women are given antibiotics sooner, usually in consultation with the gynecologist.
Neither you nor the doctor will know immediately if the treatment is working. You will only be able to find out after 2 to 3 months. With neuroborreliosis, you may even experience fatigue, memory loss, and trouble concentrating for up to 3-6 months after treatment. In this case, there is no point in continuing the antibiotic.
The risk of chronic Lyme disease is very low when treatment is well followed.
Want to know more?
- Good use of repellents – CBIP – Belgian Center for Pharmacotherapeutic Information (offers in particular a few names of specialties with a sufficient high concentration)
- Skin disinfectants – CBIP – Belgian Center for Pharmacotherapeutic Information
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