Secrets of Lyme Disease Revealed
Lyme disease is an infectious disease caused by several bacteria of the genus Borrelia. It is the most common tick-borne disease in the world, transmitted from deer ticks throughout the northern hemisphere. The disease was named after the town of Lyme, Connecticut where a number of cases were identified in 1975. A new study has now revealed that the deadly bacteria appears to hide within the lymph nodes. This finding may explain why some people suffer from repeat infections of Lyme disease.
Lyme disease is a treatable infection, but if left on its own, it can lead to debilitating and untreatable conditions. The bacterium is transmitted into humans by tick bites. Early symptoms often include headaches, fever, fatigue, depression, and a circular "bulls eye" skin rash. Later on, the disease will attack the joints, heart, and central nervous system. In extreme cases, victims can suffer from permanent paraplegia, the loss of motor or sensory function of the lower extremities.
The disease can be treated using antibiotics, but the best thing to do is prevent the bacteria from entering your body. After walking in the woods or other tick-related habitats, human skin should be thoroughly inspected and any ticks found must be promptly removed. They can be hard to get off, but the easiest way is to use tweezers and try to remove the tick head and body all at once. However, if the bacteria does get through, antibiotics should be effective within four weeks if taken during the early stages of infection.
The new study that just came out from University of California (UC), Davis has found that the Borrelia bacteria which causes Lyme disease will hide out in the lymph nodes. This triggers a significant immune response, which is unfortunately, not enough to destroy the infection.
"Our findings suggest for the first time that Borrelia burgdorferi, the bacteria that cause Lyme disease in people, dogs and wildlife, have developed a novel strategy for subverting the immune response of the animals they infect," said Professor Nicole Baumgarth, an authority on immune responses at the UC Davis Center for Comparative Medicine.
"At first it seems counter intuitive that an infectious organism would choose to migrate to the lymph nodes where it would automatically trigger an immune response in the host animal," Baumgarth said. "But B. burgdorferi have apparently struck an intricate balance that allows the bacteria to both provoke and elude the animal's immune response."
Swollen lymph nodes, or lymphadenopathy, is one of the hallmarks of Lyme disease, although it has been unclear why this occurs. The UC Davis researchers set out to explore in mice the mechanisms that cause the enlarged lymph nodes and to determine the nature of the resulting immune response.
They found that when mice were infected with the bacteria, live spirochetes accumulated in the animals' lymph nodes. The lymph nodes responded with a strong, rapid accumulation of B cells, white blood cells that produce antibodies to fight infections. Also, the presence of the bacteria caused the destruction of the distinct architecture of the lymph node that usually helps it to function normally. The result is a less than functional immune response.
For more information: http://www.plospathogens.org/article/info%3Adoi%2F10.1371%2Fjournal.ppat.1002066
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