Rocky Mountain Spotted Fever: What's Your Risk in Tennessee?

Shaina Farfel with Occupational Health discusses Rocky Mountain Spotted Fever, a tick-borne disease, with Dr. Karen Bloch, Associate Professor of Medicine and Health Policy and Medical Director for the General Infectious Disease Clinic at Vanderbilt University. She discusses the prevalence of Rocky Mountain Spotted Fever and how it can be prevented.

Begin Transcript

Shaina Farfel: Welcome to this edition of the Vanderbilt Health and Wellness wellcast.  I'm Shaina Farfel with Occupational Health.  Today we are speaking with Dr. Karen Bloch, Associate Professor of Medicine and Health Policy and Medical Director for the General Infectious Disease Clinic at Vanderbilt University.  Hi, Dr. Bloch.  Thanks so much for being with us today.

Karen Bloch:  It's my pleasure.  Thank you.

Shaina Farfel:  We are in the middle of another hot Nashville summer.  A lot of us are getting outside.  We are in our gardens.  We are maybe swimming in the local swimming holes, taking hikes.  And being outside does increase our risk for exposure to different insects and bugs, which can carry disease.  Today, I wanted to speak with you about one such disease, which is known as Rocky Mountain Spotted Fever.  Could you tell us a little bit about Rocky Mountain Spotted Fever and how it is transmitted?

Karen Bloch:  Rocky Mountain Spotted Fever is a disease that is spread by ticks, and specifically in our part of the country, by the American Dog Tick.  It is widespread.  It is in the community.  It is on our pets.  So, it is a tick that we see commonly and it is a disease that we see not infrequently this time of year.

Shaina Farfel:  Where is Rocky Mountain Spotted Fever most prevalent?  Can folks be exposed to it here in Tennessee?

Karen Bloch:  It can be found throughout the United States, but the name "Rocky Mountain Spotted Fever" is a bit of a misnomer.  It was actually initially described in the Rocky Mountain area, but is most prevalent, actually, in the southeast United States.  So, Tennessee is often a high prevalence area and in fact, there was something called the Rocky Mountain Spotted Fever Belt that extends from North Carolina to Oklahoma, transversing through Tennessee, so, we certainly are in an area where we could expect to see this disease.

Shaina Farfel:  Okay.  And so, what would I look out for?  What kind of signs and symptoms would we expect from this disease?

Karen Bloch:  Well, the first thing I want to make clear is that the tick has to be attached for a significant period of time.  So, I would like to reassure folks that if they have a tick on them and it has been there for less than six hours, the risk of developing this disease is extremely small.  On the other sort of side of the coin is that most of these ticks don't carry the disease.  So, we don't recommend treating or prophylaxing patients who have had a tick on them just by virtue of the exposure.  We do ask folks to be vigilant, though.  If you have been outside or had a tick on you, the symptoms that I would recommend folks pay attention to would be the onset of fevers, chills, muscle aches, sort of a flu-like illness happening outside of the traditional flu period.  The thing that is most pathognomonic for Rocky Mountain Spotted Fever is the rash.  This often will come on, though, after the onset of fever.  So, the absence of a rash doesn't disprove that this is the illness.  The rash typically starts around the wrists or ankles and then spreads sort of centrally towards the belly and often will spare the face.  And just as the name implies, it is a spotted rash with bright red spots.

Shaina Farfel:  If I had a tick bite and I was starting to develop some of these symptoms, and was potentially concerned about whether or not I had Rocky Mountain Spotted Fever, what would you suggest that I do, and is it treatable?

Karen Bloch:  We do recommend that folks who either have a known tick exposure, or even in the absence of a known tick exposure, who experience symptoms like fever, seek medical attention, and I think the provider can get a history that may suggest the disease.  There are also blood tests that can be suggestive.  So, specifically, folks with Rocky Mountain Spotted Fever often will have low platelet counts or elevated hepatic enzymes and those might be indirect clues for this illness, but often the diagnostic tests, which are antibody tests, are delayed.  So, we don't recommend waiting to give therapy or treatment for a positive test.  If the suspicion is there, we tell providers that the safest thing to do is go ahead and treat, and the good news is it is a very treatable disease.  There is an antibiotic called "doxycycline" that is extremely active against this infection and is indicated for folks with a high probability.

Shaina Farfel:  This is definitely something that I think most people would want to try and prevent.  How would you recommend doing so?  And how do we protect ourselves against this disease?

Karen Bloch:  So, protection is really important and there are two different sort of strategies for that.  The first is behavioral interventions.  So, if you are going outside to do things that you already eluded to, working in the garden or hiking in areas where we think ticks might be residing, we recommend wearing long sleeves or long pants or at least doing a check for ticks after being outside for any period of time.  The other approach to preventing infection is using commercial products that contain DEET and that works to prevent ticks' attachment and decreases the risk of infection.  So, we recommend both the behavioral side of things, including the buddy check for ticks, as well as applying a repellant that contains DEET.

Shaina Farfel:  Wonderful.  Well, thank you so much for being with us today.  I think you have provided us with some very valuable information about how we can increase our awareness of this disease and also prevention strategies.  So, we appreciate your time.  Thank you so much.

Karen Bloch:  Thank you.

Shaina Farfel:  Thanks for listening.  If you have a story suggestion, please email it to us at or you can use the "Contact Us" page on our website at