Lyme Disease and Related Laboratory Tests

Lyme disease is a type of infection that is caused by the bacteria Borrelia mayonii and Borrelia burgdorferi. This infection is primarily spread to humans via infected deer tick bites. They are also referred to as black-legged ticks. A person who is bitten by an infected tick might end up with an inflammatory condition. The skin is affected first, and then it might spread to other parts of the body, including the nervous system and joints.


Tiny ticks cause Lyme disease. They are around the size of a speck of dirt or the head of a pin. They may be present on any part of the body but tend to attach themselves to parts of the body such as the groin and scalp. Not everyone who discovers ticks on their bodies will be infected with Borrelia. Also, many who have been bit by a tick will not end up developing Lyme disease. That is because not all ticks are infected, and it may take 24-72 hours for the bacteria to be transmitted after the tick attaches itself to a human body.  

According to the Centers for Disease Control and Prevention (CDC) statistics, over 40,000 Lyme disease cases are reported each year in the U.S. Cases are mainly concentrated in the upper Midwest and Northeast. In 2015, approximately 95% of all Lyme disease cases that were reported came from 14 states. However, the CDC states it appears that areas that have high incidences of Lyme disease are expanding. Most of the cases take place in the spring and summer since those are the times when ticks are the most active and when people are spending more time outdoors.

The CDC estimates that the number of individuals in the U.S. who get diagnosed every year with Lyme disease is about ten times the number of cases that are reported. The higher estimate of 400,000 annual cases is based on data that comes from ongoing studies. The CDC says that the higher estimates don’t mean that many Lyme disease cases are not treated but only that they might go unreported to federal and state public health labs. When under-reporting disease estimates, it can create an inaccurate picture of the seriousness, especially when it might have a much higher incidence rate than was thought previously. More accurate estimates received from ongoing studies may help to increase awareness of this issue, and provide added incentive for the medical community, government, and general public to focus on Lyme disease as well as how to prevent it. 

Post-Treatment Lyme Disease Syndrome

Some individuals who have Lyme disease will continue to suffer from symptoms of muscle and joint aches, pain, and fatigue even after being treated with antibiotics. In a small percentage of Lyme disease cases, those symptoms may last for more than six months. It is referred to as Post-Treatment Lyme Disease Syndrome (PTLDS). The precise cause of PTLDS is still unknown. It is sometimes called chronic Lyme disease. There is ongoing research being done to better understand what causes the syndrome.

Symptoms and Signs 

Lyme disease occurs over a series of stages. The early infection is confined to an area surrounding the tick bite. Then it progresses into the early disseminated phase and finally to late Lyme disease.

Early symptoms and signs may develop from 3-30 days following the tick bite. They can include the following:

  • A rash that may appear a couple of days up to a month following the bite (about seven days is the average).  Around 70-80% of individuals who are infected with Borrelia burgdorferi end up developing erythema migrans, which is a characteristic circular rash. Typically, it spread out from the site of the bite and might grow as large as 12 inches (30 centimeters) or even larger across eventually. It might look like a bulls-eye and might feel warm to the touch. However, it is typically not itchy or painful. Some individuals might develop several red rashes while others might not have, or not recall having, a rash. It is common for redness or small bump to develop soon after getting bitten by a tick. It might resemble a mosquito bite. However, the redness or bump usually will go away within a few days and isn’t a symptom of Lyme disease.
  • Swollen lymph nodes
  • Joint and muscle aches
  • Chills and fever
  • Fatigue
  • Headache
  • Borrelia mayonii appears to produce other symptoms, which include vomiting and nausea, and might cause a more diffuse (spread out) rash that lacks the appearance of a bull’s eye target.

If Lyme disease is not treated, additional symptoms and signs might develop several days or months following a tick bite, including the following:

  • Inflammation of the spinal cord and/or brain
  • Tingling, numbness, or shooting pains in the feet or hands
  • Shortness of breath, dizzy spells
  • Changing sleep patterns, difficulty concentrating, memory loss
  • Intermittent arthritis with swelling and joint pain, particularly in large joints such as the knees
  • Eye pain, redness, irritation, and blurred vision (rare)
  • Irregular heartbeat (rare) and chest pain
  • Severe headaches and neck stiffness (meningitis)
  • Pain and numbness in legs and arms
  • Paralysis and facial weakness (Bell’s palsy)
  • Joint and muscle pain (might be intermittent)


A healthcare professional might diagnose Lyme disease if you have any of the following:

  • Symptoms and signs, like a “bulleye” rash or erythema migrans (EM).
  • Have suffered a tick bite and/or visited or live in an area where it is common to find Lyme Disease

In cases where there are enough symptoms and history for diagnosing Lyme disease, usually, a lab test is not ordered.

Lyme disease testing might be ordered if you have symptoms and signs that suggest you might have the infection. For individuals who don’t have symptoms, the CDC doesn’t recommend for Lyme disease testing to be done.

The test that is preferred is a blood test for detecting two antibody classes that the body produces to combat a Borrelia infection:  

IgG (immunoglobulin G) antibodies are unable to be detected until several weeks following the infection. Around 4-6 months later, the levels peak and stay at high levels for several years.

Borrelia IgM (immunoglobulin M) antibodies usually can be detected within the blood in around 2-3 weeks following infection. IgM levels first increase and at approximately six weeks peak and then start to decline.

The CDC recommends that two different methods be utilized to detect the antibodies as well as confirm a Lyme disease diagnosis.

Initial tests might use methods such as immunofluorescence (IFA) or enzyme immunoassay (EIA) for measuring IgG or Borrelia IgM antibodies. The initial test is designed to be quite sensitive so it can detect as many Lyme disease cases as possible. However, it may come back with positive results with infections that are caused by other types of bacteria that are like Borrelia, like syphilis or various tick-borne disease or other conditions like autoimmune disorder (e.g., lupus).

The CDC recommends that any indeterminate or positive results from an initial test should be followed up with a second test, referred to as a Western blot where specific antibodies are detected to multiple antigens so that the initial findings can be confirmed.

If you have any symptoms that suggest that your central nervous system has been affected (meningitis), then tests might be conducted on a sample of your cerebrospinal fluid (CSF).

Polymerase chain reaction (PCR) testing be performed on a sample in special cases since it is a more sensitive method of detecting a Borrelia infection. However, it has not been cleared by the FDA or approved as a test method. It also is not widely available. Currently, the CDC does not recommend PCR testing for diagnosing Lyme disease.

Usually, Lyme disease is treated using antibiotics that are taken orally for 2 to 4 weeks. Some individuals who have severe infections might need to have antibiotics administered intravenously. In most cases, people with Lyme disease recover completely and quickly. In some cases, and with late-stage Lyme disease some nerve damage and joint pain might persist.