A Lyme Disease test can be tricky for a number of reasons. Because Lyme starts out with symptoms similar to the flu or other common illnesses, it may take some time to get a correct diagnosis.
Where does Lyme come from?
In the US, Lyme comes from a tick bite from a tick that carries a bacterium called Borrelia burgdoferi. It is commonly carried by the black-legged tick, also known as the deer tick.
Ticks live off the blood of animals such as deer and rodents, some of which can be infected with Borrelia burgdoferi. The deer tick needs to latch on for at least 24 hours to transmit the disease.
The most common symptoms of Lyme in its early stage are flu-like symptoms. One of the sure signs of Lyme infection is a bullseye rash, a red spot with a white and then a red circle around it. This is one of the best ways to differentiate Lyme from other illnesses.
However, only around 70% to 80% of patients get the characteristic bullseye rash that would indicate Lyme disease. The other 20% to 30% would need a blood test to determine if Lyme were present in order to start treatment.
Some people might see an attached tick and head to the doctor for a test. It is important to note that the blood tests for Lyme are not perfect. There can be false positives, and false negatives.
The first thing a doctor should do is take a full medical history, including whether you’ve been outdoors in the spring and summer in an area where you might have picked up a Lyme-carrying tick. Lyme disease is common in northern latitudes and most particularly in the Northeastern US.
They will do a physical exam and take blood. Lab tests to identify antibodies to the bacteria in the bloodstream can help confirm whether or not you have been infected with Lyme.
Unfortunately, these tests are not always reliable in the early stages of the illness. They are not sensitive enough to detect early antibody activity. This means a false negative. A blood test several weeks later might show as positive for Lyme even though the first was negative.
You might also end up with a false positive. This is because in some cases, you might already have been exposed to Lyme. You might not even have known you were. You might not have had symptoms, or you did, but the Lyme disease was caught early and went dormant.
However, the antibodies would still be present in your bloodstream, leading to a false positive. This can be dangerous due to overtreatment, and because you have another medical condition which accounts for your symptoms, and that might go untreated because the doctor is treating you for Lyme.
The two main Lyme Disease Test Methods
The ELISA test is usually given when a person first suspects they have Lyme. It is most accurate at least 1 week after the infection has started, because your body will have had time to develop antibodies against the Lyme.
ELISA stands for Enzyme-linked immunosorbent assay and looks for antibodies to the Borellia burgdorferi bacteria.
Because it can sometimes provide incorrect results, your doctor should follow up with a second test, the Western blot test.
If the ELISA test is positive, the Western blot test is usually done to confirm the diagnosis in order to avoid any false positives. The Western blot test detects antibodies to several proteins of Borrelia burgdorferi, so it is more accurate.
If you think you or a family member might be suffering from Lyme disease, it’s time to get tested so you can get the correct treatment.