Laboratory Tests That Detect Lyme Disease
Clinical diagnosis is just not sufficient to detect Lyme disease because the symptoms are closely similar to those of many other diseases. Headaches, joint pain and numbness in the legs, arms, hands and feet, which are usually associated with Lyme disease, are also present in many other diseases. Therefore, the clinical diagnosis has to be supported by diagnostic tests to confirm the presence of Lyme disease. Several tests may have to be done as the patient may not test positive for some tests. Only if the same results are corroborated through other tests can the patient be considered to be free from the disease. Multiple tests help to rule out the possibilities of any other diseases that might cause the symptoms. It also helps the doctor to correlate the findings with other patients who suffer from the disease that makes it easy to arrive at a conclusion.
Testing for Lyme disease
ELISA applications are widely used for testing Lyme disease along with two more tests such as the Western Blot test and Polymerase Chain Reaction (PCR). While the first two tests are commonly done for all patients, the third one is applicable for patients suffering from nervous system symptoms or persistent Lyme arthritis. The ELISA and Western blot tests are done to detect antibodies that might be present in the patient’s blood, which could have been triggered by an infection with bacteria B. burgdoferi and spirochete. However, the presence of the antibodies does not confirm if the infection is still present. Thus the tests are an indirect way of detecting the disease.
Not only Lyme disease but a number of other diseases can also be screened by ELISA (Enzyme Linked Immunosorbent Assay) that has gained popularity in testing HIV. It is an inexpensive test that is also used to detect West Nile virus, pernicious anemia, syphilis, rotavirus, RMSF, squamous cell carcinoma and many other diseases. The blood sample is tested by using a marker enzyme that is attached to an antibody and a change in color is considered an indication of the presence of antigen.
Western Blot test
This blood test also depends on a color change that happens to the blot. However, it is a qualitative test and not a quantitative one like the ELISA. Being subjective in nature, the correct interpretation of the test result depends on the skill of the laboratory technician who has to assess the intensity of the color bands to conclude the presence or absence of bacteria. In modern methods of testing, the subjectivity has been removed by using automated testing methods.
Polymerase Chain Reaction
Moving away from the indirect methods of detection of Lyme disease, PCR is a more specific method of testing that is capable of detecting the organism’s genetic material. While the other tests provide indirect leads about the infection based on the immune response, PCR pinpoints the genetic material thereby leaving nothing to chance. A positive PCR result therefore underlines the presence of infection that is very current or present.
Until now, these are the most reliable tests for Lyme disease.
Article by Tom Evans, who has been associated with consumer healthcare for more than a decade. He has worked in the African subcontinent extensively in his fight against HIV and AIDS. With a background in chemistry, he takes special interest in ELISA applications.