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WMS Blog Entry No. 4, Part II: Tick Lifecycle and Diseases in Colorado

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There are two types of ticks in Colorado: soft and hard. Hard ticks have a plate on the back of their head like armor and mouth parts that are visible and directed forward. Hard ticks are differentiated by soft ticks how? You guessed it: Soft ticks do NOT have that plate on their head and their mouthparts are not visible because they lie beneath the tick.

Life cycle of tick graphic taken from https://extension.uga.edu/publications/detail.html?number=C937&title=Protect%20Yourself%20from%20Ticksextension

Ticks have 4 stages of life: Adult ticks lay thousands of 1) eggs which hatch as 2) 6-legged tiny larva which develop and mold into 3) 8-legged young adult nymphs. After eating and developing yet again, the nymphs turn into 4) adults. Depending on tick type, the larvae, nymph, and adult ticks can be active and feed on blood. While ticks in most of the country develop over 1 year, ticks commonly encountered in Colorado usually require 2-3 years to develop.

While there are 27 species of ticks in Colorado, the two seen with most prevalence are the Rocky Mountain wood tick and the brown dog tick. Almost all human encounters with ticks here involve the Rocky Mountain wood tick, as this tick resides in the western U.S. and southern Canada at elevations between 4,000 and 10,000 feet.

Tick sensing its host! Courtesy of Tick-Borne Disease WMS Presentation

The adult Rocky Mountain wood tick feeds on larger mammals and humans and can carry the bacteria that cause RMSF, Colorado tick fever and tularemia. The adult tick climbs onto vegetation and waits ever so patiently until it detects vibrations, exhaled carbon dioxide, and warmth that passing mammals give off.

Adult Female and Male Rocky Mountain wood tick, photo courtesy of Colorado Ticks fact sheet

Brown dog ticks are found at lower elevations and warmer areas, and seem to only develop on dogs. Not surprisingly, these ticks are found in areas where dogs are kept in close quarters, such as kennels and homes.

Fun Fact: Most hard ticks are 3-host ticks, meaning they feed from one host and then drop from that host after each feeding (blood meal) to develop into the next stage.

Not so fun fact: Hard ticks can survive a whole year without feeding! These ticks also become dormant with high temperatures in late spring and summer, meaning they are most active in the spring. On the other side of the spectrum, soft ticks feed more briefly and frequently than hard ticks, feeding several times before they develop into the next stage.

Tick Borne Diseases:

The most common tick-spread disease in Colorado is Colorado Tick Fever with around 200 cases reported in Colorado per year. This disease is caused by a virus and is carried by the Rocky Mountain wood tick. Those infected may experience headache, fever, chills and fatigue that occur 1-14 days after the tick bite. Special to this disease is that symptoms are biphasic, meaning you will get very sick for a couple of days, then feel better (recovery phase), then become sick again. Since this disease is viral in origin, treatment is supportive, meaning medication is given to decrease your symptoms such as headache and fever.

Despite its name, Rocky Mountain spotted fever is a rarely diagnosed disease in Colorado, with around 3 reported cases per year. This serious and potentially life-threatening disease caused by the bacteria Rickettsia rickettseii is carried by both the Rocky Mountain wood tick and Brown dog tick, and has higher prevalence along the east coast in states such as North and South Carolina. This bacterium can spread from tick to human in only 6-10 hours of the tick being attached, a relatively short exposure time when compared to other tick borne diseases such as Lyme disease, which requires around 36 hours of attachment in order to spread. Early symptoms can appear within 3-12 days after tick contact and include headache, fever, upset stomach and myalgia (muscle aches). A notorious rash on the palms of the hands and soles of the feet may appear a few days after the fever onset and spread to involve the rest of the body. As this disease is caused by bacteria, it is treated with antibiotics. If you experience fever, headache, nausea, vomiting, muscle pain or a rash after possible tick exposure, seek help!

While considered a tick-borne disease, Tularemia caused by the bacteria Francisella tularensis, can also be transmitted directly by contact with infected blood of animals such as rabbits and prairie dogs during activities such as hunting. The ticks known to transmit this disease are the Rocky Mountain wood tick and American dog tick. Historically, Tularemia prevalence in Colorado was low, however there were 52 documented cases in 2015, occurring mostly in Boulder and Larimer counties.  Symptoms most commonly include swollen lymph nodes (lymphadenopathy) and if spread to the respiratory tract, infections such as pneumonia. This disease may also present with localized symptoms of skin ulcers at the location of contact of tick bite or animal blood.  Antibiotics will cure this disease.

Tick-borne Relapsing Fever, caused by the bacteria Borrielia hermsii, is quite rare in Colorado as well. It is carried by the soft tick Ornithodorus hermsi and associated with nesting rodents. This disease is usually spread when a person is bitten by this tick while sleeping in cabins where rodents are present. Symptoms occur in a 3-day cyclical pattern and include high fever, headache, and muscle and joint aches. Since it is bacterial, this tick-borne disease is treated with antibiotics as well.

Not caused by a virus or bacteria, Tick paralysis is a reaction to tick saliva caused by neurotoxins produced in the salivary glands of the female Rocky Mountain wood tick. This can occur if the tick remains attached for a long period of time. Symptoms include difficulty walking within hours to a day of tick exposure and can progress to limb numbness and difficulty breathing. While this sounds frightening, there is good news: these symptoms are COMPLETELY reversible once the tick is removed, with symptoms resolving in days to a week.

A tick talk is never complete without discussing Lyme Disease, the most prevalent tick-borne disease of humans in the US. While there have been some cases reported in Colorado, it is thought the disease originated from a black-legged tick exposure outside the state in areas from Massachusetts to Virginia, Utah, and southern Washington to northern California.  This spirochete-type bacterium (borrelia burgdorferi) is carried by black-legged ticks (deer ticks). You may not see an attached tick with this disease, as it is not the adult, rather the nymph and larval stage ticks that transmit this bacterium. The nymph and larvae look more like tiny black or pale brown dots and are extremely difficult to see during tick checks. Symptoms include the infamous non-itchy red bull’s eye rash that develops within the first month of the bite. Again, you can see generalized flu-like symptoms such as headache, fever, chills and fatigue. It is reported that early recognition and treatment can result in complete recovery, and reduces the risk of arthritic, neurologic or cardiac complications that can develop days to years later.

The infectious diseases that ticks may carry can definitely wreak havoc. This is why it is important to do what you can to prevent tick bites while enjoying the beautiful outdoors. Read Part I of this post on Tick-Borne Illness here.

References

  1. Cranshaw W, Peairs F, Kondrateiff B. Colorado Ticks and Tick-Borne Diseases Fact Sheet. Colorado State University Extension. https://extension.colostate.edu/topic-areas/insects/colorado-ticks-and-tick-borne-diseases-5-593/. Accessed August 5, 2020
  2. Author Unknown (2016, July). Quandry: Ticks in the High Country and what they can do to you. Summit Daily. https://www.summitdaily.com/opinion/quandary-ticks-in-the-high-country-and-what-they-can-do-to-you/ Accessed August 5, 2020
  3. DeLoughery, T. (2020, July). Tick Borne Disease. Presentation through Wilderness Medicine Society Virtual Conference. Accessed September 5, 2020.

Laurie Pinkerton is a 3rd year Physician Assistant Student studying at Drexel University in Philadelphia, PA. Originally from Northern, VA, she graduated from the University of Mary Washington in Fredericksburg, VA with a degree in Biology in 2014. She moved to Keystone to live that ski life and stayed for 2 years, working as a pharmacy tech at Prescription Alternatives and as a medical assistant at Summit Cardiology. Prior to starting PA school, she moved to Idaho where she learned about organic farming and alternative medicine.  She has loved every second of being back in Summit County and learning here at Ebert Family Practice. She looks forward to practicing Integrative Medicine in the near future.

Backcountry, Backpacking, Health, High Altitude, Medicine, Mountaineering, Wildlife

WMS Blog Entry No. 4, Part I: Tick Bite Prevention and Proper Removal

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Ticks are blood feeding parasites. Ticks are known as vectors because they can transmit different pathogens responsible for several diseases including Colorado Tick Fever, Rocky Mountain Spotted Fever (RMSF), Tularemia and relapsing fever. While there are 27 species of ticks in Colorado, almost all human encounters w/ ticks in Colorado involve the Rocky Mountain wood tick, a tick that only lives in the western U.S. and southern Canada at elevations between 4,000 and 10,000 feet. Another highly prevalent tick is the brown dog tick which is specific to dogs.

Before you go out!

DO:

  • Wear protective clothing! Wearing long sleeved shirts, long pants tucked into your socks and close toed shoes can keep ticks from getting onto your skin, as ticks are usually acquired while brushing against low vegetation.
    • wear light colored clothing, as this makes it easier to find ticks that have been picked up
    • Treat clothing w/ permethrin as this can help kill or repel ticks for days to weeks! Do not apply directly to skin.
  • Use Tick repellent. This includes the well-known DEET along with picaridin, IR3535 and oil of lemon eucalyptus
    • Repellent can be applied either directly to skin or to clothing, AND is most effective if applied to the lower body that is likely to come in contact with ticks first!
    • If applying repellents to skin:
      • DO NOT use high concentration formulas on children (DEET concentration > 30)
      • AVOID applying repellents to your hands or other areas that may come in contact with your mouth
      • DO NOT put repellent on wounds
      • ALWAYS wash skin that has had repellent on it.
  • Remember: Dogs can get ticks too! Don’t forget to consult your veterinarian about how to protect your furry friends against ticks.

When you go out: DO NOT assume that you won’t get bit.

  • Avoid tick habitat
    • Ticks are most active in spring and early summer and are concentrated where animal hosts most commonly travel, including areas of brush along field and woodland edges or commonly traveled animal host paths though grassy areas.
      • DO try to avoid exposure in these areas by staying in the center of marked trails when hiking to avoid brushing vegetation that ticks may be perched on waiting for you!
    • If possible, avoid these sites during tick season.
    • If you live in known tick territory, you may even get a tick bite in your own backyard! Decrease this risk by creating a tick-free zone around your house by keeping your lawn mowed, eliminating rodent habitats (wood or rock piles) around your house, and placing wood chips between your lawn and tall grasses or woods.

After coming back inside

  • Perform a tick check which includes botha visual and physical inspection of your entire body, as well as your gear and pets. Because ticks take several hours to settle and begin feeding, you have time to detect and remove them. You tend to not feel ticks because their saliva has histamine suppression and analgesic effects. Ticks like warm, moist and dark areas but can latch anywhere.
    • Examine your scalp, ears, underarms, in and around the belly button, around the waist, groin/pubic area, buttocks and behind your knees.
    • If camping, perform tick checks daily on humans AND pets, making sure to examine children at least twice daily. Again, pay special attention to the head and neck and don’t forget to check clothing for crawling ticks.
    • Shower and wash your clothes after returning home from the outdoors.

If you or a family member get bit by a tick: DO NOT PANIC, and DO NOT immediately rush to the emergency room! If the tick has been attached for less than a day, the chance of the tick transmitting one of these diseases is low. Removing ticks can be tricky, as they use their mouthparts to firmly attach to the skin.

Best method for tick removal -> remove as quickly as possible!

1. Grasp the tick with fine tipped tweezers as close to the skin as possible. If tweezers are not available, use a rubber gloved hand or place tissue or thin plastic over the tick before removing it to avoid possible transmission of disease.

2. Pull tick SLOWLY and with STEADY PRESSURE STRAIGHT away from the skin

  • DO NOT:
    • Crush, puncture, twist or jerk the tick as you remove it. This may increase risk of the tick regurgitating infected body fluids into the skin or leaving mouthparts in skin

3. After the tick is removed, disinfectant the attachment site on skin and WASH YOUR HANDS. Dispose of the live tick by placing in a sealed bag/container and submersing it in alcohol, then wrapping it tightly and crushing it in duct tape, OR flushing it down the toilet.

  • DO NOT:
    • crush the tick in your fingers
    • try to suffocate the tick still on the person by covering it with petroleum jelly OR touching it with a hot match to suffocate -> these methods can cause the tick to burst and INCREASE time the tick is attached, as well as making the tick more difficult to grasp

Remember: the goal is to remove the tick quickly from the host as opposed to waiting for it to detach on its own.

If you remove the tick and are worried, you can always put the tick in a sealed container with alcohol and bring the dead tick to your medical provider.

If you develop a rash or flu-like symptoms (fever, fatigue, body aches, headache) within several weeks of removing tick, see your medical provider and tell him/her about the recent tick bite, when it occurred and where you acquired the tick.

Remember: These diseases are very treatable if caught early enough!

Graphic taken from https://www.cdc.gov/ticks/pdfs/FS_TickBite-508.pdf

Stay tuned for next month’s explanation of the tick life cycle and tick-borne diseases in the high country!

References

1. Colorado Tick and Tick Born Diseases fact sheet. https://extension.colostate.edu/topic-areas/insects/colorado-ticks-and-tick-borne-diseases-5-593/ Accessed on 8/8/20

2. Peterson J., Robinson Howe. P. Lyme Disease: An Uptick in Cases for 2017. Wilderness Medicine Magazine: https://www.wms.org/magazine/1213/Lyme-Disease. Accessed 8/8/20

3. Do’s and Don’t’s of Tick Time: https://awls.org/wilderness-medicine-case-studies/dos-and-donts-of-tick-time/ Accessed 8/8/20

Laurie Pinkerton is a 3rd year Physician Assistant Student studying at Drexel University in Philadelphia, PA. Originally from Northern, VA, she graduated from the University of Mary Washington in Fredericksburg, VA with a degree in Biology in 2014. She moved to Keystone to live that ski life and stayed for 2 years, working as a pharmacy tech at Prescription Alternatives and as a medical assistant at Summit Cardiology. Prior to starting PA school, she moved to Idaho where she learned about organic farming and alternative medicine.  She has loved every second of being back in Summit County and learning here at Ebert Family Practice. She looks forward to practicing Integrative Medicine in the near future.

Acclimation, Altitude Science, Athletic Training, Backcountry, Backpacking, Health, High Altitude, High Altitude Training & Fitness, Mountaineering

WMS Blog Entry No. 3: Pre-acclimatization, A Synopsis of Dr. Peter Hackett’s Lecture

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What is pre-acclimatization? It is a process of adjusting to a new climate, usually higher elevation, reducing hypoxemia in high altitude settings in turn saving time, money, and most importantly, reducing altitude sickness. It can also allow for better sleep/comfort and physiological/cognitive performance at a high altitude. Acclimatization is a time-dependent process as over 5,000 genes are impacted by a large shift in elevation affecting ventilation, plasma volume, and hemoglobin mass, among other things. The whole process is not completely understood, but one key element is the hypoxic ventilatory response (HVR). HVR is activated by the aortic artery baroreceptors, as oxygen in the blood reduces it triggers an increase in respiration. This happens immediately as you ascend in altitude and maximizes at 7-14 days. Arterial oxygen increases by an increase in ventilation/saturation and also by dropping plasma volume, increasing hemoglobin concentration, and then later on, increasing overall Hgb production which in theory, overall decreases altitude sickness.

So how can you prepare yourself or pre-acclimatize?

Some of the better-known methods are spending time at higher altitudes prior to your destination, using a hyperbaric or normobaric chamber, blood doping, hypoxic exercise training, and a few pharmaceutical methods. All of these are options, but the key question is, which ones truly work?

Pre-acclimatization with actual altitude is the most useful. Generally speaking, you would pick your maximum sleeping altitude at your destination and slowly work your way towards that altitude. You pick an ascent profile which preferably would be spread over a week or more to be most useful. This pre-acclimatization should be completed no more than 1-2 weeks prior to your destination so that any pre-acclimatization gained doesn’t wane prior to your trip.

Simulated altitude is another option which includes hypoxic tents, hypoxic rooms/homes, hypoxic exercise chambers, and hypoxic masks. Out of these four, hypoxic tents or hypoxic rooms/homes, where exposure is over a long duration, are by far the most effective. Hypoxic masks and exercise chambers are not very effective as their short duration does not give the body enough time to make the proper adjustments and although might be beneficial in respiratory muscle training/performance, do little in the way of pre-acclimatizing your body. Studies show more benefit from hypobaric hypoxia training vs normobaric hypoxia training but keep in mind studies are very limited and warrant much further research. Overall, simulated altitude minimum requirements look to be somewhere in the range of 1 week of exposure, 7 hours per day, and a minimum effective altitude of 2200-2500 m and being no more than 1500-2000 m below your target sleeping altitude. Shorter term protocols can attenuate altitude sickness but not the incidence some studies suggest. As to why hypobaric methods are more effective than normobaric methods, no one really knows yet and more research is needed.

Changing your living destination to something at a much higher elevation and exposure over years or moderate altitude residence (MAR), is the most effective method according to some studies, but this is far from feasible for most. There are studies to show epigenetic changes for those who relocate to higher elevations for long periods and these appear to be much less than those who have genetically adapted to higher elevation over generations but still more effective than the previous mentioned short-term options.

Hikers often camp at the Angel of Shavano campground before ascending Mt. Shavano, one of Colorado’s famed fourteeners.

Oxygen saturation is maximal at 11 days of exposure to a specific elevation. Diamox (acetazolamide) increases ventilation and can help with acclimatization but there isn’t much data on how using this pharmaceutical compares to other methods mentioned. World-renowned high altitude expert and pioneerDr. Peter Hackett theorizes that it may fall just short of MAR, but again, more research is needed. Short-term altitude exposure shows benefits at 7 days but a longer exposure such as 15 days has been shown to be much more beneficial.

Blood doping with EPO can be somewhat effective over a 4+ week treatment and can potentially decrease AMS and potentially increase exercise performance but the data is limited and conflicting on this. Also, it appears that it is only effective up to 4,300 m but not beyond that as arterial oxygen content is not the determining factor for sleep and cognition performance at high altitudes but rather oxygen delivery which is affected by hematocrit and viscosity of blood.

Hypoxia inducible factor (HIF) is a regulatory factor in cells that respond to a reduction in oxygen, causing changes in about 5000 different genes to help the body adjust to meet oxygen requirements. It is suggested that we could pharmaceutically activate this factor prior to destination in order to acclimatize the patient allowing for less complications and better results at higher elevations. Currently there are some drugs in trials but nothing specifically FDA approved.

Overall, data and studies are limited but the most effective current pre-acclimatization method is long-term altitude training (real or simulated). If possible, plan your ascent trip to be slow and steady to obtain best results with the least amount of complication.

Joel Miller is currently preparing to graduate from Red Rocks Community College’s reputable Physician Assistant program this Fall. He has been a resident of Colorado for four years where he has immensely enjoyed the outdoors camping, fishing, hiking, hunting, and exploring Colorado’s wide variety of breweries.