The Test Sample
What is being tested?
Lyme disease tests measure Borrelia burgdorferi antibodies in the blood or in the cerebrospinal fluid (CSF) if there are signs and symptoms of central nervous system disease. These antibodies are produced by the body's immune system in response to exposure to Borrelia burgdorferi (B. burgdorferi), the bacterium that causes Lyme disease. Infected deer ticks or western black legged ticks transmit this bacterium to a person through a bite. The disease is most common in the spring and summer in the regions where these ticks live, such as the northeastern, mid-Atlantic, north-central, and western United States.
Lyme disease infection causes symptoms that may include a characteristic erythema migrans (EM) or "bulls-eye" rash that spreads from the site of the bite, fever, chills, headache, and fatigue. If left untreated, Lyme disease may progress to cause intermittent joint pain, meningitis, facial paralysis (Bell's palsy), weakness and numbness in the arms and legs, memory problems, and may rarely affect the heart or eyes.
It takes the body some time to begin producing B. burgdorferi antibodies. B. burgdorferi IgM (immunoglobulin M) antibodies are usually detectable in the blood about two to three weeks after exposure. IgM levels increase to maximum concentrations at about six weeks and then begin to decline. IgG (immunoglobulin G) antibodies are detectable several weeks after exposure, increase to maximum levels at about four to six months, and may remain at high levels for several years.
Two tests are typically used to detect and confirm Lyme disease. The Centers for Disease Control and Prevention (CDC) recommend that an ELISA or IFA test method be used first to measure B. burgdorferi IgM and/or IgG antibodies. Since these tests may be positive with infections caused by other bacteria similar to B. burgdorferi, such as the bacterium that causes syphilis, the CDC recommends that any positive or indeterminate test results then be followed by a second test, called a Western blot, in order to confirm the findings.
How is the sample collected for testing?
A blood sample is taken by needle from a vein in the arm. If there are symptoms of meningitis, a sample of cerebrospinal fluid (CSF) is collected by a doctor from the lower back using a procedure called a lumbar puncture or spinal tap. Sometimes a sample of joint fluid (synovial fluid) from an infected joint will be drawn.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.