Monday, June 22, 2020

Microbe of the Week: Borrelia burgdorferi

Photo credit: Janice Haney Carr, CDC Public Health Image Library
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 


Photo Credit: CDC Public Health Image Library
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: 

Friday, June 19, 2020

Community Contributors: Now that's a lot of ticks!

It is tick season folks.  And nothing reminds us of this more than all your help reporting on tick activity and collecting specimens.

Earlier this week we received a photo from a Carlton County contributor who sent us this photo:

Photo by E. Felien, June 2020

Each little black speck represents a tick, the whole bunch was collected over the course of a week.  Not all of them are the species responsible for transmitting Lyme disease, Ixodes scapularis (deer ticks), but other species of ticks can also spread various diseases.

So please, when enjoying the great outdoors, protect yourselves from tick bites, and when you do encounter ticks, let us know!

You can self report tick encounters at on our Tick Risk Story Map website (here) and then send us your specimens at: 


University of Minnesota Duluth
Ixodes Outreach Project
1035 University Dr.
Duluth, MN  55812
Attn: SMed 332

When submitting a specimen please include the following information:

Date found
Whether it had been attached to a human or animal or found unattached
Location where the tick was likely picked up
Optional: your name, mailing address and email address for follow up correspondence

Ideally, ticks are best preserved if they are stored in a Ziploc bag or small, airtight container with a dab of hand sanitizer gel to coat the tick.  However, ticks that have dried out can still be useful to our research.  When mailing, please keep in mind that a small baggie can usually be sent without extra postage and handling, however, sending tubes or rigid containers of ticks requires mailing specimens to us in a box to avoid damage.

Should you be interested, we would be happy to send you a Tick Kit with additional information, tick collection and submission information and a tick removal key.  Kindly send your mailing address and we will get a kit out in the mail to you.



Check out our Ixodes Outreach Project Story Map Website:  http://z.umn.edu/Ixodes


-photos and text by C. Fisher

Tuesday, June 16, 2020

Notes from our crew: Why isn’t there a human vaccine for Lyme disease?

This post is prepared by Zoe Quinn, a volunteer undergraduate researcher.

While there are plenty of preventative treatments like vaccines for our furry friends, you may be asking yourself why there are not more options for yourself. The current available methods for human prevention include reducing exposure to ticks or treatment after a suspected tick bite. What about a vaccine? In fact, in 1998 there used to be a Lyme vaccine called LYMErix. Since then, this product has been pulled from the market due to reports of adverse reactions which resulted in a lawsuit and a large decrease in vaccine sales. Despite the claims of adverse reactions, the FDA determined that there was no causative association between the vaccine and the reactions. Fortunately, there is a new vaccine called VLA15 that has been created by a company called Valneva. It’s currently being tested and interim Phase 2 data should be expected mid-2020!
Read more about this topic through the National Library of Medicine:

See Valneva’s website for updates about VLA15