Lyme's desease

What is Lyme disease?

Lyme disease is a infection caused by Borrelia, a type of bacteria called a spirochete. Lyme disease can affect any part of the body, most commonly the skin, central nervous system, joints, heart, and rarely the eyes and liver.

Lyme disease is common in parts of the United States (particularly Massachusetts) and Europe, but it is reported in many areas of the world. In New Zealand and Australia, cases have only been confirmed in people who have recently traveled from a endemic zone.

Lyme disease is also called Lyme borreliosis.

See more images of erythema migrans.

What are the subtypes of Lyme disease?

There are different types of Borrelia on each continent that result in various forms of Lyme disease in North America and Europe.

In North America, the infection is due to the subspecies. B. burgdorferi sensu stricto and more often it is presented as:

• Migratory erythema (also called chronic migratory erythema)
• Lyme arthritis

In Europe, Lyme disease is due to the subspecies B. burgdorferi sensu stricto, B. afzelii and B. garinii, and more frequently it appears as:

• Migratory erythema
• Borrelial lymphocytoma

• Chronic atrophic acrodermatitis (this is due to B. afzelii)

• Lyme neuroborreliosis.

How is borrelia infection spread?

Humans and animals become infected with the bacteria through hard tick bites. Borrelia survive in the midgut of ticks. Immature nymphs are more likely to transmit the infection. Ticks feed on infected animals and then humans.

Ticks occur in tall grasses, thickets, forests, and lush forests. The main Hosts Ticks and borrelia are small to medium-sized animals in Europe and deer in North America.

• In North America, the tick vectors They are Ixodes scapularis, I. pacificusand 4 other tick species
• In Europe and Asia, tick vectors are I. ricinus, I. hexagonusand I. persulcatus

Who gets Lyme disease?

Lyme disease can affect children and adults. The infection occurs more frequently in forest workers and those who have been enjoying recreational activities in areas where ticks reside.

What happens after a tick bite?

Ticks can attach to and feed on any part of the human body. The bite is painless. Because they are so small (only 2mm in size), nymph bites are often overlooked. Borrelia is transmitted from the midgut of the infected tick to the attached skin when the insertion lasts 36 to 48 hours.

Several things can happen after being bitten by an infected tick.

• The body's defense mechanisms can overwhelm and kill infecting bacteria.
• The bacteria can remain located at the site of the bite and cause a localized skin infection.
• The bacteria can spread through the blood and lymphatic system to other organs and cause a multisystem inflammatory disease.

What are the signs and symptoms of Lyme disease?

The disease can be divided into three stages depending on the extent of the infection.

Migratory erythema

Migratory erythema, an expansive red patch of skin, is the most typical. sign of Lyme disease and is present in 70 to 80% of cases. It usually appears between 7 and 14 days (range between 3 and 33 days) after the bite of the infected tick. Starts at the site of the tick bite as a red papule or taint gradually expanding The size of the eruption It can reach several dozen centimeters in diameter. A central spot surrounded by light skin which in turn is surrounded by an expanding red rash (like a Diana) is the most typical appearance. Migratory erythema can also present as a uniform erythematous red patch or patch with central hardening and blisters. The redness can vary from pink to very deep purple.

The migratory erythema is mainly asymptomatic, but can cause itching, tenderness, or heat if touched. It is rarely painful. Fatigue, chills, headache, low fever, muscle and joint pain, may occur briefly and then come back if the disease progresses. The lymph glands near the tick bite may be swollen.

The migratory erythema disappears spontaneously in 3 to 4 weeks. If left untreated, the disease can spread, affect other organs, and progress to the next stage.

How is Lyme disease diagnosed?

Early diagnosis of Lyme disease is essential. The presence of migratory erythema and other symptoms can be diagnosed, in addition to a history or evidence of a tick bite. Laboratory tests are generally not necessary in the early stage of migratory erythema,

Early undetected or ignored symptoms can be followed by more severe symptoms weeks, months, or even years after the initial infection. Certain laboratory tests are recommended to confirm the diagnosis and must be interpreted by an expert.

• Antibody titles to B burgdorferi using enzymelinked immunoassay (ELISA) or immunofluorescent assay.
• Positive results should be confirmed by western blot.

• Skin biopsy: histopathology

  • Migratory erythema is often not specific
  • Borrelial lymphocytoma
  • Chronic atrophic acrodermatitis
• the organism can be cultivated or Polymerase chain reaction (PCR) the test for the organism can be done on the skin sample.

Positive antibodies B. burgdorferi can be detected in many cases for many years after successful treatment.

Tick bites can transmit other infections such as tick-borne encephalitis, anaplasmosis, and babesiosis. Co-infections should be considered if the symptoms of Lyme disease are severe or prolonged, in case of high fever and abnormal blood test results (leukopenia, thrombocytopeniaor elevation of liver transaminases).

What treatment is available for Lyme disease?

Localized or early Lyme disease generally responds well to appropriate antibiotics. Complete healing is usually achieved if the disease is diagnosed and treated promptly, but the cure rate decreases as treatment is delayed. The choice of antibiotic depends on bacterial sensitivity.

Antibiotics used for migratory erythema include doxycycline, amoxicillin, and cefuroxime. Second-line treatments are macrolides, azithromycin, and erythromycin. Intravenous penicillin and cetriaxone are used for more advanced Lyme disease. The route of administration and the duration of the course of antibiotics depends on the stage and the involvement of the organs. It varies between 10 and 30 days. Late stage Lyme disease, especially neuroborreliosis, should be treated with intravenous antibiotics.

Some patients have persistence or recurrent symptoms of unknown origin after apparently successful antibiotic treatment for Lyme disease. This is called post-treatment Lyme borreliosis. syndrome. It is believed to be an autoimmune response. Prolonged antibiotic treatment does not improve cure rates.

Lyme disease prevention

• Avoid areas endemic for Lyme borreliosis.
• When walking in tall grass or woods, wear white clothing (so that the tick can be seen more easily) with long sleeves, long pants tucked into socks, or long boots.
• Use repellents / pesticides.
• After returning from a walk in an endemic area, change your clothes and check your entire body carefully.
• The next day, check your body for ticks again.
• Remove the tick as rapid removal decreases the risk of transmission of Lyme disease. Disinfect the site. Use tweezers to carefully and constantly pull the tick out of the skin. Disinfect the site again. Wash your hands.
• Look at the site of the tick bite for several weeks. If a rash appears larger than 5 cm or you have flu-like symptoms, see your doctor.

There is no vaccine for Lyme disease.