Lyme Disease

Definition

Lyme disease is a bacterial infection that affects skin, bones, and eventually the nervous system and heart. The bacteria is transmitted by ticks, which are carriers of the disease from animals such as deer to humans. It is not contagious among humans. Part of the disease is due to the infection itself and part of the reaction is a result of an immune response initiated by the bacteria. Therefore Lyme disease can be an ongoing condition even after the bacterial infection resolves, as the immune response may persist over the long term.

Symptoms

Lyme disease starts with an itchy rash called erythma migrans that has an oval/circular or a bull’s eye appearance. The disease progresses slowly and may take several weeks to months for other symptoms to develop. With the spread of the infection in the body and the immune response, several other symptoms follow, which include :

  • Flu like symptoms – fever, chills, headache, body ache
  • Stiff neck
  • Joint pain – if untreated, severe joint pain and swelling develops several weeks after the initial infection. This affects movement.
  • Swollen lymph nodes
  • Severe fatigue

It can also damage the nervous system. The symptoms can include inflammation of the meninges (membranes surrounding the brain), paralysis of one side of the face (Bell’s palsy), impaired muscles movement. Less than 10% people may develop symptoms of the heart which includes irregular heartbeat, dizziness or shortness of breath. These symptoms last only for a short time. In rare cases eye inflammation may develop

Causes

Lyme disease is caused by the bacterial species Borrelia –  Borrelia burgdorferi in USA and Borrelia afzelii in Europe. Ticks that feed on the blood of the host are carries of this disease. They transmit the disease from a diseased animal to a human. During feeding, the ticks can pick up the bacteria from an infected animal.

When feeding again, they can then transmit these bacteria to the new host. They normally feed on deers or mice. They can also feed on other warm-blooded animals such as cats, dogs and humans, thereby transmitting the disease to humans. The bacteria enter the skin when the ticks are feeding and they eventually enter the blood stream.

Since these ticks are very small, they are difficult to spot. Therefore it is necessary to be careful in the outdoors, especially in areas with grass or woods, and in areas with a higher risk of Lyme disease. Wearing long sleeves and long pants and using insect repellents is advisable to prevent tick bites. Tick infections are most common during the summer. Children playing outdoors are at a higher risk.

Treatment

Lyme disease is treated using antibiotics. Antibiotics are administered orally, when the disease is in the early stage. Doxycycline is used to treat adults and children older than 8 years. For younger children and pregnant women, amoxicillin or cefuroximes is normally used. In cases where the disease has advanced, an intravenous antibiotic may be prescribed. This is effective but usually with other side effects such as a low white blood count, diarrhea and a greater risk of other secondary infections by other microbes.

After the prescribed antibiotic treatment and complete elimination of bacteria, some people still continue to experience some symptoms of Lyme disease such as muscle aches and fatigue. The reason for this is yet unknown but appears to be a residual immune reaction.

 

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