Clinical Information

Lyme disease is a multisystem and multistage tick-transmitted infection caused by spirochetal bacteria in the Borrelia burgdorferi sensu lato (Bbsl) complex.(1) Nearly all human infections are caused by 3 Bbsl species; B burgdorferi sensu stricto (hereafter referred to as B burgdorferi) is the primary cause of Lyme disease in North America, while Borrelia afzelii and Borrelia garinii are the primary causes of Lyme disease in Europe. In 2012, Borrelia mayonii was identified as a less common cause of Lyme disease in the upper Midwestern United States.(2,3) This organism has only been detected in patients with exposure to ticks in Minnesota and Wisconsin and has not been detected in over 10,000 specimens from patients in other states, including regions of the northeast where Lyme disease is endemic.

Lyme disease is the most commonly reported tick-borne infection in Europe and North America, causing an estimated 300,000 cases in the United States each year and 85,000 cases in Europe.(4,5) The clinical features of Lyme disease are broad and may be confused with various immune and inflammatory disorders. The classic presenting sign of early localized Lyme disease caused by B burgdorferi is erythema migrans (EM), which occurs in approximately 80% of individuals. Other early signs and symptoms include malaise, headache, fever, lymphadenopathy, and myalgia. Arthritis, neurological disease, and cardiac disease may be later stage manifestations. EM has also been seen in patients with B mayonii infection, but diffuse rashes are more commonly reported.(2) The chronic skin condition, acrodermatitis chronicum atrophicans, is also associated with B afzelii infection.

The presence of EM in the appropriate clinical setting is considered diagnostic for Lyme disease; no confirmatory laboratory testing is needed. In the absence of a characteristic EM lesion, serologic testing is the diagnostic method of choice for Lyme disease.(6) However, serology may not be positive until 1 to 2 weeks after onset of symptoms and may show decreased sensitivity for detection of infection with B mayonii. Therefore, detection of Bbsl DNA using polymerase chain reaction (PCR) may be a useful adjunct to serologic testing for detection of acute disease. PCR has shown utility for detection of Borrelia DNA from skin biopsies of Lyme-associated rashes and can be used to detect Borrelia DNA from synovial fluid and synovium biopsies. Less commonly, Borrelia DNA can be detected in cerebrospinal fluid and blood.(7) In general, blood is not the preferred source for detection of Bbsl DNA by PCR, although it may have increased utility for detection of B mayonii, due to the higher levels of observed peripheral spirochetemia with this organism.(2) Lyme PCR should always be performed in conjunction with US Food and Drug Administration approved serologic tests, and results should be correlated with serologic and epidemiologic data and clinical presentation of the patient.(8) The Mayo Clinic Lyme PCR test detects and differentiates the main causes of Lyme disease in North America (B burgdorferi and B mayonii) and Europe (B afzelii and B garinii).(2,7)