What is Borreliosis?

Borreliosis is a world-wide infectious disease caused by spiral-shaped bacteria of the genus Borrelia, which is carried by ticks and louse. The two groups of Borrelia known to cause disease in humans are:

  • B. burgdorferi group that causes Lyme disease and
  • The Relapsing Fever borrelia group that cause Relapsing Fever. Click here for more information on Relapsing Fever.

What is Lyme Disease?

Lyme disease is caused by Borrelia species, collectively known as Borrelia burgdorferi sensu lato. The disease is named after the town of Lyme in Connecticut, USA, where a group of children with an unusual arthritic condition were studied. The causative agent of Lyme disease was identified by Prof. Willie Burgdorfer as a spirochetal bacterium, and named after him as Borrelia burgdorferi. Lyme disease, now known to be caused by the European species B. afzelii, was first described over 100 years ago in Europe from characteristic early stage disease, skin rash erythema chronicum migrans (EM), and from the late stage disease, skin rash acrodermatitis chronica atrophicans  (ACA).

B. burgdorferi sensu lato currently includes at least 18 species of Borrelia. B. afzelii, B.  bavariensis, B. bissettii, B.  garinii, B. kurtenbachii, B.burgdorferi  sensu stricto, B. spielmanii, B. lusitaniae, and B. valaisiana are found in Europe.  B. burgdorferi sensu stricto, B. carolinensis, B. bissettii, B. californensis,  B. andersonii, and B. mayoni are found in the US. Three most important human pathogenic species are B. burgdorferi sensu stricto in the USA and Europe, and Borrelia afzelii and Borrelia garinii in Europe and Asia.

Lyme borreliosis (LB) caused by B. burgdorferi sensu stricto causes a multisystemic disease that can affect many organs, including the heart, joints, central nervous system, and the brain.  B. afzelii causes a distinct skin infection known as ACA and B. garinii is associated with early Lyme neuroborreliosis (i.e., painful meningoradiculoneuritis or Bannwarth syndrome).

How Is Lyme Disease Transmitted?

The Lyme disease causing Borrelia are transmitted to humans by hard ticks.

Hard Ticks



Currently two species of deer ticks, the eastern black-legged tick, Ixodes scapularis, and the western black-legged tick, I. pacificus, are known vectors for B. burgdorferi, the causative agent of  Lyme disease in the US. In Europe and Russia, the vector is I. ricinus and in Asia I. persulcatus.

These ticks also transmit pathogens for several diseases, including Relapsing Fever disease, Anaplasmosis, and Babesiosis. A typical transmission takes place when an unsuspecting human or animal walking through woodlands or brushy areas is bitten by a tick. The tiny ticks, some the size of poppy seeds, may stay on the body for hours to days without the host realizing they are there. The tick engorges itself with blood, and if infected, the spirochete is transmitted to the bloodstream of the person or animal during the bite.

What Are the Infected Regions?

Lyme disease is prevalent in US, Europe, Middle East, and parts of Asia and Australia.

What Are the Symptoms?

A characteristic red bulls-eye rash, known as Erythema Chronicum Migrans (EM), may appear at the site of the bite within days to weeks after exposure, but it is present in less than 40% of patients. Other symptoms reported by patients include flu-like symptoms, fever, aches, fatigue, neck stiffness, jaw discomfort, muscle pain and stiffness, swollen glands, and red eyes. Nervous system abnormalities may include memory loss and partial facial paralysis (Bell’s palsy). Migratory joint pains, and pains in the tendons, muscles and bones may occur later in the disease. Arthritic symptoms, if present, usually affect the large joints like the knees. Symptoms may appear, disappear, and reappear at various times.

Click here on how to order a test kit from IGeneX. Test kits can be ordered by both patients and physicians.

FOR HEALTHCARE PROFESSIONAL:  Click here for more information on the type of diagnostic tests for Borrelia.

Can A Tick Be Tested?

At IGeneX, ticks can be tested for the presence of B. burgdorferi sensu lato group by a PCR test. Any tick, including the one that has been removed from a patient, can be sent to IGeneX for testing.

Click here for more information on how to test a tick.