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Microbe of the Week is written by undergraduate researcher, Maria Bergquist.
Microbe of the Week: Borrelia burgdorferi
Welcome to microbe of the week, where we break down the different disease-causing microbes that lurk inside our tick vectors! This week we will be discussing
Borrelia burgdorferi, the most common causative agent of Lyme disease in the United States.
What is Borrelia burgdorferi?
Borrelia burgdorferi is a spirochete bacterium—that is, a single-celled organism that exists in a spiral shape. A powerful tail, called an endoflagellum, runs along the entire body of the bacterium and is how most spirochete bacteria travel. This tricky bacterial species is known for its ability to hide from the immune system. Its disguises include using the saliva of the tick as a shield and can even change the expression of proteins on its outer surface!
B. burgdorferi’s relatives
While
Borrelia burgdorferi sensu stricto (Latin for strictly speaking) is the most common causative agent for Lyme disease in the United States, other strains of the Borrelia genus can also cause Lyme disease. These strains include
Borrelia afzelii and
Borrelia garinii which are found in European and Asian countries, as well as
Borrelia mayonii (found first in Minnesota in 2013) and
Borrelia miyamotoi which was first found in Japan in 1995 and has since spread to the United States.
Symptoms
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Photo Credit: CDC Public Health Image Library
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Symptoms for Lyme disease can be debilitating if not caught and treated quickly. The most common early symptom is a rash called Erythra migrans (EM). The CDC describes EM as a red rash that “begins at the site of a tick bite …. expands gradually over several days …. [and] may be warm to the touch but is rarely itchy or painful”. While it is known to have a bullseye shape, rash shape and size may vary. EM is known to occur in 70 to 80% of Lyme disease cases.
Other early symptoms—between 3 and 30 days post tick bite—include “fever, chills, headache, fatigue, muscle and joint aches, and swollen lymph nodes”.
Later stage symptoms as described by the CDC include:
- Severe headaches and neck stiffness
- Additional EM rashes on other areas of the body
- Facial palsy (loss of muscle tone or droop on one or both sides of the face)
- Arthritis with severe joint pain and swelling
- Intermittent pain in tendons, muscles, joints, and bones
- Heart palpitations or an irregular heart beat (Lyme carditis)
- Episodes of dizziness or shortness of breath
- Nerve pain
- Shooting pains, numbness, or tingling in the hands or feet
Treatment
Treatment for Lyme disease requires the use of antibiotics and is most effective when started in the early stages of the infection.
More details on Lyme disease treatment is available at the CDC website:
A Condensed History
- 15 million year old tick preserved in amber found to be infected with spirochetes related to Borrelia species: https://www.tandfonline.com/doi/abs/10.1080/08912963.2014.897699
- 5300 year old human found infected with Borrelia on the border of Italy and Austria. The mummy was named Ötzi the Iceman.
- 1883 – First recorded case similar to late stage Lyme disease recorded by German Doctor Alfred Buchwald.
- 1909 – Swedish dermatologist Arvid Afzelius describes bullseye rash and links symptom to tick bite.
- 1970s – Cases of pediatric arthritis start popping up in Lyme, Connecticut. By the mid-1970s these cases were termed Lyme disease and antibiotic treatment was recommended.
- 1981 – Willy Burgdorfer discovers unknown spirochete, later named Borrelia burgdorferi to honor him.
- 2015 – CDC has 30,000 reported cases annually, though estimate as much as 300,000 unreported cases.
- Present – Lyme disease is currently the most common vector-borne illness in the United States.
A more in-depth historical review of Lyme disease is available at:
