7 Tick-Borne Diseases (Besides Lyme) to Watch Out For on the AT

My number one fear as a thru-hiker? Ticks. Yes, really. Is it that crazy to be afraid of a many-limbed, blood-sucking monster so minuscule I might not even notice when it bites me?

Sure, they’re tiny, but I maintain that it’s perfectly reasonable to be terrified of an eight-legged poppy seed when you consider that just one bite could transmit diseases with potential life-altering complications.

At least a bear I can see coming, and my rational brain can remind me that it’s more afraid of me than I am of it. Ticks have no such qualms—and the brushy, forested Appalachian Mountains are absolutely crawling with them.

Ticks can transmit serious diseases to unsuspecting humans when they bite us. And many species are so tiny that you might not even notice you were bitten.

Most people think of Lyme disease when they think about ticks, but it’s not the only illness to worry about. If you’re planning to hike the Appalachian Trail, here are a few tick-borne illnesses (other than Lyme) to be aware of.

Ed. Note: We are hikers, not doctors. This advice is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified health care provider with any questions you may have regarding a medical condition. 

Deer Tick Diseases

Adult female deer tick. Photo by Scott Bauer, Public domain, via Wikimedia Commons.

While Lyme is the most common (and infamous) disease transmitted by deer ticks, it’s far from the only one. Deer ticks (also known as blacklegged ticks) are common in all 14 states the AT passes through.

They tend to live in tall grasses and shrubs in moist, shaded areas, often climbing to the end of a long blade of grass to wait for unsuspecting prey to brush past.

Deer ticks tend to be most active (and your risk of getting bitten is higher) between early spring and mid-fall, although bites are still possible year-round.

Although mature deer ticks are roughly the size of a sesame seed, many of the diseases they carry are more commonly spread to humans during the nymph stage of the life cycle, when the tick is roughly the size of a poppy seed.

READ NEXT – Bears, Noro, and Lyme: What to Worry About (Or Not) on Your Thru-Hike


AT States: MD, NJ, NY, CT, MA, VT, NH, ME. Hikers likely to encounter highest concentration of cases in MA

Incubation period: 1-9+ weeks

Symptoms: Flu-like symptoms, nausea, dark urine; less common: enlarged spleen and liver, jaundice, dizziness, confusion, rapid heart rate, heart murmur

Babesiosis is a rare, life-threatening infection of the red blood cells most commonly caused by the parasite Babesia microti. Babesiosis is rare, but the highest concentration of cases in the US is roughly centered around Massachusetts.

It is transmitted by the deer tick, just like Lyme disease. Also like Lyme, immature ticks (nymphs) are more likely to transmit the disease than mature adults. Babesiosis is unlikely to transmit until the tick has been attached for at least 36 hours.

READ NEXT – How to Not Mistake Lyme Disease for Coronavirus

Powassan Virus

AT States: PA, NJ, NY, CT, MA, NH, ME
Incubation Period: 1-4 weeks
Symptoms: Fever, headache, vomiting, weakness; may progress to seizures, palsies, altered mental status, movement disorders, aphasia

This emerging disease is still extremely rare, with just a handful of cases reported nationally each year. However, case frequency is on the rise.

Whereas many tick-borne diseases require a relatively long attachment period to transmit to humans, you can catch Powassan virus from a tick in as little as 15 minutes after getting bitten. Moreover, ticks at any stage of the life cycle (larvae, nymphs, and adults) can all transmit the virus.

There is no specific treatment for this illness other than supportive treatment for symptoms.


AT States: NC, TN, VA, WV, MD, PA, NJ, NY, CT, MA, VT, NH, ME

Incubation Period: 5 -14 days
Symptoms: Fever, chills, headache, fatigue, stiff joints, nausea, diarrhea, vomiting, anorexia; less than 10% of cases display a rash

Anaplasmosis is found in every AT state except Georgia, but it’s most common in the northern states (Pennsylvania and up). The disease is caused by the bacterium Anaplasma phagocytophilum.

The tick must be attached for at least 12-24 hours to transmit the disease to humans. Like Lyme and babesiosis, anaplasmosis is most likely to be spread by nymphs rather than adults.

Similar to Lyme disease, doxycycline is typically the recommended treatment. Anaplasmosis can be a serious illness, though it is only fatal in about 1% of cases.

READ NEXT – Let’s Talk About Ticks and Tick-Borne Illness

Lone Star Tick Diseases

Adult female lone star tick. Judy Gallagher, CC BY 2.0, via Wikimedia Commons.

The Lone Star tick is somewhat larger than the deer tick. Adult females are most likely to bite you and are easily identifiable by the characteristic white spot on their back. They live in woods, especially areas with thick undergrowth. White-tailed deer are their primary host species. They are most active, and you are most likely to get bitten, between spring and fall.

Heartland Virus

AT states: GA, NC, TN
Incubation period: Unknown, most sufferers report symptoms within 2 weeks
Symptoms: Fever, stiff/aching joints, headache, nausea, diarrhea, loss of appetite

Heartland Virus was first discovered in Missouri in 2009, but it has since spread to states including Tennessee, North Carolina, and, more recently, Georgia, so AT thru-hikers in the southern states should be cautious.

Heartland is still quite rare, so there’s no routine testing protocol for this disease and experts still don’t know everything about it.   It is rarely fatal, but sufferers are often hospitalized to treat symptoms.


AT States: All
Incubation Period: 3-5 days
Symptoms: Fever, headache, fatigue, anorexia, stiff joints, chest pain, sore throat, vomiting, diarrhea, abdominal pain, lesions at infection site, swollen lymph nodes

Tularemia can be transmitted by lone star ticks, dog ticks, deer flies, or handling infected animals. It is highly contagious, meaning if you’re exposed you’re pretty likely to get it, but it doesn’t spread from human to human—you have to get it directly from a fly, tick, or animal.

Tularemia has been reported in all 14 AT states but isn’t very common in any of them. It’s pretty rare in general, infecting 200-300 people nationwide each year. Interestingly, unlike most tick-borne diseases featured in this article, tularemia has actually become significantly less common over the last 70 years.

I couldn’t find any info on how long a tick has to be attached to transmit tularemia, but since it can also be transmitted by biting flies (which don’t tend to hang around once they’ve chomped you), I would assume transmission can happen very quickly.

The disease is caused by the bacterium Francisella tularensis and can be treated with a variety of antibiotics.

READ NEXT – How to Prevent Lyme Disease on the Appalachian Trail


AT States: All
Incubation Period: 5-14 days

Symptoms: Fever, headache, fatigue, muscle pain, nausea, vomiting, diarrhea, anorexia, altered mental state, red eyes, rash (especially in children)

Ehrlichiosis is found in all 14 states on the Appalachian Trail, but case concentrations are highest in Tennessee, North Carolina, Maryland, New Jersey, and Vermont. The disease is most commonly caused by the bacterium Ehrlichia chaffeensis. Typically, the tick must be attached for at least 24 hours to transmit ehrlichiosis.

If left untreated, this disease can have serious and life-threatening complications, including kidney or heart failure, hemorrhaging, and neurological complications. Doxycycline is the most commonly recommended treatment.

Ehrlichiosis can be transmitted by multiple kinds of ticks, including deer and dog ticks, but the lone star tick is the most common vector.

Dog Tick Diseases

Adult female dog tick. Ryan Hodnett, CC BY-SA 4.0, via Wikimedia Commons.

American dog ticks are among the most common ticks east of the Mississippi River. They have dark brown bodies with a whitish (female) or mottled (male) shield on their backs and are one of the larger tick species. Like deer ticks, they prefer wooded/shrubby areas and long grasses. Dog ticks are most active, and you are most likely to get bitten, in spring, summer, and fall. (Did I say “ticks” enough times in that paragraph? I’m not sure.)

Rocky Mountain Spotted Fever

AT States: All
Incubation Period: 5-14 days

Symptoms: Fever, headache, rash (late onset), nausea, vomiting, stomach pain, muscle pain, loss of appetite, confusion

Despite its name, Rocky Mountain Spotted Fever (RMSF) can be found throughout most of the United States and is much more common in the southeast and south-central US than in the actual Rocky Mountains. It is found in every state on the AT, though the highest concentration of cases occurs in North Carolina, Tennessee, Virginia, Maryland, and New Jersey.

Some, but not all, people infected with RMSF develop a non-itchy, splotchy or pinpoint rash starting on the wrists or ankles a few days after the first onset of symptoms. Serious complications including organ failure or long-term neurological impacts can develop if left untreated. RMSF is typically treated with antibiotics, especially doxycycline.

Both nymph and adult dog ticks can spread RMSF, but the tick must be attached for 24-50 hours in order to transmit the infection.


Also transmitted by lone star ticks—see the lone star tick section for more information.


Also transmitted by lone star ticks—see the lone star tick section for more information.

What have we learned?

Remember, blacklegged tick = deer tick. Graphic via US Centers for Disease Control.

I think we can all agree that ticks are the absolute worst—however, I hope you won’t let that fact discourage you from getting outside and exploring the backcountry. The threat of tick-borne diseases is not to be taken lightly, but it can certainly be managed. Avoid dense grass and brushy areas, regularly apply insect repellent to your skin and permethrin to your gear, and check yourself for ticks every night.

If you do get bitten, note the species, whether it’s already engorged, and where on your body it bit you. Keep an eye on that spot in case a rash develops (although the presence or absence of a rash doesn’t prove anything on its own) and monitor your health for at least a few weeks.

You should at the very least take a picture of the tick before discarding it, or at best, save it and mail it off to a testing center to find out if it was carrying any diseases.

If you develop symptoms that don’t go away, it’s worth considering whether you might have a tick-borne illness. Let your doctor know that you’ve been frolicking in the woods lately (and definitely tell them if you’ve been bitten) so they’ll take that possibility seriously as well.

Most importantly, arm yourself with knowledge ahead of time. We have a wealth of Lyme disease and tick safety-related content on The Trek so you can study up before your next hike.

Further Reading

Bears, Noro, and Lyme: What to Worry About (Or Not) on Your Thru-Hike
How to Prevent Lyme Disease on the Appalachian Trail
How to Not Mistake Lyme Disease for Coronavirus
How to Prevent Lyme Disease on the Appalachian Trail
Ticks – Centers for Disease Control

Featured image: Adult female dog tick. Ryan Hodnett, CC BY-SA 4.0, via Wikimedia Commons.

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Comments 1

  • Bart : Jan 27th

    Before the AT I sent all my clothes to a company in Roanoke called “Insect Shield”. They infuse permethrin into the fabric itself, and will last many, many washing.
    I sprayed my entire tent and ground cloth with permethrin.
    I always forwarded a “bounce box” about every 100 miles, and in it I carried a bottle of permethrin to re-spray my shoes, gaiters, gloves.
    Never sit down in the leaves or grass. Put something under your bottom.
    Be very aware if you get off the trail to dig a cat hole. Better yet, just stick to using the shelter privy’s.
    I wore shorts and kept my legs shaved so I could look down and inspect my legs after I walked through grass/bushes.
    I used the Sawyer Picaridin on my legs if it was a bushy/grassy day. It’s also SO MUCH easier to apply bug lotion without hair on your legs.


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