Tick-borneborreliosis (Lyme disease)

An infectious disease caused by spirochetes and transmitted by ticks, with numerous clinical manifestations, mostly being chronic and recurrent, affecting the skin, nervous, musculoskeletal system and heart.

Lyme disease is the most common disease in the Northern Hemisphere transmitted to humans by ticks.

Cause of tick-borne borreliosis (Lyme disease)

Causative agents of tick-borne borreliosis are spirochetes of the Borrelia typefrom the genus Ixodes. A causative agent of systemic tick-borne borreliosis enters the human body with saliva. A migrating circular erythema develops at the site where a tick is attached.From the site of attachment, the agent with lymph and blood penetrates into inner organs, joints, lymphatic and nervous systems. When dying, borrelia produces an endotoxin, which triggers the cascade of immunopathological reactions. Borrelia can stay in the human body for several years causing a chronic disease with multiple recurrences.

Symptoms ofLyme disease

There are three consecutive stages of the disease.

Stage 1 (acute) is characterized by general infection symptoms of intoxication (fever, headache, muscle soreness, malaise, somnolence, etc.) and erythema migraines.The erythema occurs at the site of the tick bite and represents a gradually increasing in its diameter patch with dark red outer edge and clear in between. Stage 1 develops a few days or weeks after a tick bite and the infection with spirochetes, it lasts up to 1 month. After the first, acute stage, a patient can either recover, or enter the chronic course (stage 2 and 3). At stage 2, the nervous system or the heart is affected. Due to the nervous system involvement, the patient presents with peripheral neuropathies (numbness of the extremities), meningitis, radiculitis etc. Cardiac damage is characterized by palpitations, cardiac pains, blocks, etc. Stage 2 can last fora half a year. At stage 3, the patient develops arthritis associated with either nervous system, or heart pathology, depending on the target organ involved at stage 2. Besides arthritis, atrophic dermatitis is rather common at stage 3.

Diagnosis of tick-borne borreliosis

IgMantibodies to borrelia appear in the blood 2-4 hours after the infection and are detected within half a year. Analyses done immediately after the bite are non-informative. IgGantibodies appear 4-6 weeks after erythema and are revealed in the blood within several years even if the disease has resolved at  stage 1. Single determination of the titer of IgGantibodies  gives no information. For revealing the dynamics of the process, IgGantibodiestiter should be determined twice with an interval of 4-6 weeks. If the titer of antibodiesdecreases, the disease resolves.

Treatment ofTick-borne borreliosis (Lyme disease)

The treatment of tick-borne borreliosisshould be complex and includeetiotropic and pathogenetical medication depending on the stage of the disease. If an antibacterial therapy was started at stage 1 of the disease and was appropriate, neurological, cardiac and arthralgic complications are less likely to develop. A marked exacerbation of symptoms during the antibacterial therapy is not rare (as when treating other diseases caused by spirochetes). This is due to massive death of spirochetes when endotoxins invade the blood. The patients are administered restoratives and adaptogens, vitamins A, B and C.

Vital prognosis

The vital prognosis is favorable but a patient can become disabled following the nervous system and joints involvement. Restricted professional activity isassociated with an overload on the affected organs.

Preventionof Lyme disease

Clothing should be correctly chosen either for the outdoor work, or for the rest, walks in the parks and forests. Protective clothing should include a headdress or scarf, light-colored long-sleeved clothing tight cuffs and long pants tucked into boots, closed shoes.Repellents must be used (for repelling ticks).

A thorough check of the skin and the scalp after walking, working or resting at the endemic area is highly recommended.

A correct removal of a tick. The tick should be pulled out with tweezers or fingers wrapped in bandage as close as possible to the site of its attachment to the skin. While holding it at a right angle to the skin, scroll the insect body around its axis and remove it from the skin.The site of the bite should be treated with an antiseptic (70% alcohol, brittle-green solution,5% iodine solution). The hands should be washed with soap. The tick should be placed in a clean glass container and brought to a laboratory of a Sanitary and Epidemiological Station for determining whether it is a carrier of borreliosis. If there is no possibility to examine the tick, it should be poured with boiling water or burned.

A regular check of the site of the bite and taking a temperature within 30 days for revealing the first signs of Lyme disease should be done. The doctor should be visited if the following symptoms are present: red patch with clearly defined edges at the bite site with a diameter of 3 cm or more, headache or vertigo without any obvious cause, back pains, fever to 37,5°C. The prophylactic course of antibiotics is recommended after a tick bite. Penicillin, macrolides, tetracycline, cephalosporin are administered according to the rational scheme for 5 days, if started immediately after the bite, or for 14 days, if started more than 3 days after the bite. The medication is prescribed by aninfectious disease physician taking into account the age and the condition of the patient.

T.A.Pivovarova, Head Doctor of the “Minsk Regional Dermatovenerological Dispensary”