Lyme Disease
Lyme Disease

Lyme disease is an infectious bacterial disease mainly caused by Borrelia burgdorferi. Other species of this bacterium are also found which are less likely to cause the disease. These bacteria spread through the skin bites from the deer ticks. You are more likely to develop the disease if you spend more time in the woods where the ticks thrive.

Most of you may feel worried if you are bitten by the tick but the fact is that the risk of developing the disease is very low even if the tick is carrying the infectious agent. Deer ticks transmit the Lyme infection only up on feeding on the host blood for at least 36 hours. Thus, the risk of infection is as low as 1.2% to 1.4% even in the common geographical zones of this disease.

Symptoms and diagnosis

The symptoms of the disease can be categorized into 3 stages

Stage 1: If you or your child has been bitten by the tick, then you should observe the bitten site for the presence of any expanding redness (called the erythema migrans- EM). The color is uniform, and the size of the lesion slowly increases to up to 20 cm over a few days or weeks. The rash becomes skin colored at the center as it expands. Soon the rash develops into a series of rings resembling a bull’s eye. Burning and itching of the rash are reported. Nearly 10-20% of the people with the Lyme disease can develop multiple rashes. The rash usually disappears after 4 weeks of its appearance.

If the rash does not expand and stays only for 1 or 2 days, then it is not due to the bacterial infection but is possibly due to the salivary components of the tick.

Stage 2: As the bacteria spreads to the other body parts further symptoms of the disease develop. These include flu-like symptoms such as the fever, chills, sore throat, visual disturbances, headache, muscle pain, fatigue and enlarged lymph nodes which may develop after several weeks of the tick bite. Numbness and tingling sensation can also develop.

Stage 3: If the infection is not treated, you may develop severe complications after a few weeks, months or even years. These symptoms include a severe headache, arthritis of large joints, disturbed heart rhythms, and several brain disorders effecting mood, memory, and sleep.

If you develop the erythema migrans, you should consult a physician for further diagnosis and treatment. ELISA is performed to detect the antibodies produced by the body against the bacteria. Western blot technique confirms the ELISA test. Blood tests may not be beneficial to know the presence of the infection. This is because the blood tests of the infected person may be negative for 2-6 weeks.

How is Lyme disease treated?

If you are bitten by the tick, your healthcare provider may either treat the signs and symptoms of the infection or may prescribe antibiotics as a preventive measure.

Treatment in the early stages of the infection leads to a better recovery.

Antibiotics may be given 72 hours after the removal of the tick. Doxycycline is prescribed for children above 8 years and adults. Adults may be prescribed with 200 mg single dose of the tablet while children may be prescribed up to 4 mg/kg body weight.

Antibiotic treatment for pregnant or breastfeeding women and children younger than 8 years involves the administration of cefuroxime and amoxicillin.

A 14 to 21 days course of antibiotics is given to treat long-term or chronic Lyme disease.

Symptoms such as joint and muscle pain may be persistent even after the treatment and will improve gradually.

Some tips on prevention of the disease

Avoid the habitats where the ticks are present excessively. A moist, shaded environment, with low-lying vegetation in an overgrown grassy habitat, is favorable for the growth of the ticks.

If you cannot avoid the areas infested with ticks, then wear light colored outfits to easily spot the ticks and remove them before they get strongly attached to your skin. Wear full-sleeved shirts tucked in the pants, and socks or shoes to prevent the ticks from reaching your skin. Ticks are generally present at the ground level, so an additional protection may be provided with high-heeled boots.

Apply permethrin which kills the ticks immediately as they come in contact. Insect repellants containing DEET (n,n-Diethyl-m toluamide) can also be applied to the clothes or the exposed skin. They are safe for both children and adult skin.

The bacteria do not spread before 36 hours of attachment of the tick to the skin. So check your skin daily for the presence of any attached ticks and remove them immediately. Adopting a proper way to remove the embedded tick from the skin is important to prevent the tick from releasing the bodily fluids into the wound. Hold the tick with a set of fine tweezers and pull it backward without any jerks or twists. Do not squeeze the tick as its bodily fluids contain the infectious organism. Do not use kerosene, Vaseline, liquid soap or nail polish remover, to remove the tick. Wash your hands thoroughly with an antiseptic after removing the tick. Do not be alarmed of the leftover parts of the tick as the bacteria are present in the midgut of the tick.

Preventive antibiotics may be prescribed by your doctor based on the identification of the deer tick and the signs of erythema migrans rash.

By following certain strategies, the abundance of the ticks can be reduced in their endemic residential areas. Clear off the leaf-litter, wooden piles, and the fallen trees to allow more sunlight which can cut down their population.  Application of pesticides in the residential areas is also a good intervention to suppress the tick growth.

Be vigilant! Don’t assume that you won’t be infected. Check your children and yourself for the presence of any attached ticks if you stay in the endemic areas of the deer ticks. Identify the symptoms and consult the doctor at the earliest. Early diagnosis of the infection approached with a proper antibiotic therapy is the best strategy to prevent advanced stages of illness and morbidity from the disease.

 

Reference

  1. http://www.cdc.gov/lyme/
  2. http://www.nhs.uk/conditions/lyme-disease/pages/introduction.aspx
  3. Abramowicz M. Treatment of Lyme disease. Med Letter 2000;42:37-9.
  4. Auwaerter PG,  Aucott J, Dumler JS.  Lyme borreliosis (Lyme disease): molecular and cellular pathobiology and prospects for prevention, diagnosis and treatment. Expert Rev Mol Med, 2004:1-22.
  5. Bateman H, Sigal L.  Update on Lyme Carditis. Curr Infect Dis Rep, 2000;2(4):299-301
  6. Coulter P, et al., Two-year evaluation of Borrelia burgdorferi culture and supplemental tests for definitive diagnosis of Lyme disease. J Clin Microbiol, 2005;43(10):5080-4

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