Lyme disease is caused by the transfer of bacteria in the human by the vector. Ticks are the vectors and the reservoir for these bacteria is mice and deer. The bacteria enter in the ticks when they feed on the reservoir. When these vector ticks feed on the humans, the bacteria multiply and enter in to the human. Various immunological reactions occur in the body against the bacteria which results in fever and inflammation and also neurology and cardiac effects. The bacteria may also evade the immune system b changing the surface antigen so that immune cells are unable to recognize the bacteria.
How Is The Body Affected By Lyme Disease?
The infection is caused by the bacteria Borrelia. This bacterium has got amazing ability to survive in both the vector body as well as the host body. It is interesting to that both the vector and host bodies are significantly different from each other. Even these environmental diversities, the bacterium survives. Different challenges for the survival of bacterium in both vector and host threatens the existence of bacterium. For instance, tick sucks blood almost two times in a year. Thus, to survive in the vector with minimum nutrition is a challenge. Further, human body contains a variety of highly sophisticated immune system cells which would kill the bacterium. Thus, the challenge is to survive in the human body by evading the immune system.
When the spirochetes are injected in the human by tick, an inflammatory rash, known as erythema migrans develops. This bacterium reaches to the various organs of the body such as joints, nervous system and heart. The immune system of the body tries to kill the bacteria and if the immune system fails, the infection ensues. It is interesting to note that this bacterium does not have any toxin or pyrogen such as lipopolysaccharide rather it contains a variety of lipoproteins. These lipoproteins are responsible for initiating the inflammatory process in the body. Further, B cells have their effect on the resolution of the symptoms of arthritis.
The complications at various sites such as joints, nervous cells and heart is due to the body’s response to release various chemicals in response to the invasion of bacteria at these places. This causes inflammation and swelling of joints and also causes tendonitis and carditis. Macrophages also play a major role in phagocytosis of bacteria. In spite of these immune responses, the bacteria succeed in evading the immune system. The exact cause of this is unknown however the proposed mechanism for evading immune system is through continuous change in the surface antigen.
Symptoms of Lyme Disease
The symptoms caused by the Lyme disease are the one that occurs when the immune system interacts with the bacteria. Further, the symptoms are also experienced in cases where the bacteria exert its harmful effect on the organ. Following are the symptoms of Lyme disease:
Circular Red Rash Around The Tick Bite: The rash may appear even after 2 to 3 weeks from the tick bite day.
FEVER: As the immune system starts fighting against the infection there is a rise in the body temperature.
Muscle And Joint Pain: Joint Pain is an important symptom in Lyme disease as the infection may affect the joint and related muscles.
Neurology: In cases of severe infection and when the infection is not treated in the early stage, nervous system also gets affected.
Cardiac Effects: Cardiac abnormalities also occur in cases of severe infections.
Tiredness, fatigue and headache are other symptoms of the Lyme disease.
The symptoms in the Lyme disease is generally due to the immunological response to bacteria. The symptoms may include the fever and headache. Further, organ specific symptoms are inflammation and swollen joints, tendonitis, neurological disorders and cardiac abnormalities. The mechanism by which bacteria evades the immune system is not known but it is proposed that it does by changing surface antigen. However, the disease can be effectively treated with recommended antibiotic therapy.