Lyme disease is an infection caused by the Borrelia burgdorferi bacterium which is spread to humans by infected ticks from in the genus Ixodes.
Is every tick bite dangerous?
Only about 30% of ticks on the Belgrade territory are infected with Borrelia bacterium and can spread the infection. It is more likely to become infected if the tick is attached to your skin for more than 24 hours. That is why it is very important to examine the skin carefully for the ticks, after each visit to the nature, even if you went to a city park.
Ticks are active from spring when vegetation grows, until late autumn when leaves fall of trees. Their most active period is from May to June. Ticks live on plants (grass, fallen leaves, shrubs, lower trees up to 1.5 meters above the ground max). They feed on the blood of humans and animals, and if they are infected by the bacterium that causes Lyme disease, it will spread to humans during their feeding. Ticks can stay on the skin for a several hours looking for a suitable place to bite a host. When a bite occurs, the host does not feel it because ticks have a natural anaesthetic in their saliva.
If it attaches to a human or an animal, it feeds on their blood for 2 to 7 days, and then falls off. The probability of an infections after a tick bite is only about 1%. Ticks do not transmit tetanus infection, so antitetanus protection is useless in these cases.
What are Lyme disease symptoms?
Symptoms of Lyme disease will show between a week and a month following a tick bite. The first sign are round red lesions around the bite site with dusky centres (erythema migrans). Similar changes can occur in several locations on the body. Not everyone will have redness around the bite, but if they do, it is a sure sign that they are infected with Lyme disease.
Skin lesions may be accompanied by the flu-like symptoms (headache, fever, fatigue, joint pain), lasting for several weeks if a person does not see a doctor who will prescribe antibiotics, but sometimes symptoms can be very discreet, and go unnoticed. More serious complications can occur weeks and months after a tick bite, and the disease is systemic, attacking the whole organism, nervous system, joints and heart apart from the skin.
What to do in case of a tick bite?
The longer the tick stays on the skin, the greater the chance to spread the disease, so it is important to see a doctor during the first 24 hours. No chemical agents (ether, alcohol, gasoline) should be applied to the bite site. You should not try to pull out the tick by yourself, because by pressing and squeezing it, you can cause the mouth-parts to break off and remain in the skin. Instead, you should contact a health centre. Trained staff will pull out the tick entirely, and disinfect the bite site. Sometimes, if the tick is deep in the skin, it is necessary to remove it surgically.
How is Lyme disease diagnosed?
The diagnosis is made , in addition to anamnestic data, based on the clinical picture and serological tests. Serological tests (blood analysis) detect antibodies that are formed after infection with Borrelia burgdorferi, which are present 3 to 6 weeks after the bite. The diagnosis is often difficult because in about 50% of the cases, the tick bite goes unnoticed. Also, the removed tick can be examined in the laboratory in order to detect the causative agents of the disease. Negative result does not mean that the infection is not present.
Lyme disease treatment
It is very important that the diagnosis of the disease is made as early as possible and to start the treatment as soon as possible. Antibiotics are effective especially at an early stage of the disease, when they should be administered at the maximum recommended doses and for a sufficient period. A particular problem are patients with chronic Lyme disease, when it is necessary to include intravenous antibiotics, and the effect of treatment is often seen only after a week-long, sometimes even longer, antibiotic therapy.