Managing the Tick Problem

• By Ralph Morini
• /
• March 2019-Vol.5 No.3
• /
• 3 Comments

Ticks have fast become the pest of greatest personal health concern to gardeners and outdoor people of all stripes. With good reason. They are everywhere, hard to detect and can carry debilitating, even deadly diseases. While there is no silver bullet, there are things we can do to reduce our risks, including knowing the enemy and its habits, understanding how to react when bitten and how to minimize the tick population in our yards and gardens. This article will try to briefly summarize our latest information.

The Tick Life Cycle

The three tick types of most concern to Virginians are the blacklegged or deer tick, the lone star tick and the common dog tick. Ticks are arthropods and all share 4 life stages:

• Egg
• Larva (six legs)
• Nymph (8 legs)
• Adult (8 legs).

Tick life stages: Photo: cdc.gov

Eggs typically hatch in the early spring. The tick then progresses through its life stages: finding a host, having a blood meal and dropping off the host to molt to the next stage until the adult female drops off her host to lay eggs. The greatest bite danger for humans is late spring through summer. Ticks may live for two to three years until they acquire their blood meals and progress through their adult/egg laying stage.

Blacklegged tick life cycle: www.cdc.gov

The three ticks we are concerned about carry different diseases, but the ticks (and diseases, too) share many common characteristics. They thrive in wooded, grassy areas and prefer damp environments. Ticks become progressively less active at temperatures below 45 degrees F. Activity also slows during hot dry periods. Note however that while activity increases or slows down during different seasons and in different environments, it never goes to zero. It is always smart to take precautions when in tick territory.

Ticks aren’t born infected with disease. They pick diseases up from infected hosts and carry them through subsequent stages in their development. Nymphs are probably the most dangerous transmitters to humans because they are very small and often go undetected. Adult ticks can also transmit disease but are much larger and more likely to be removed quickly. CDC data says that for blacklegged ticks, 10-36% of nymphs and about 60% of adults are infected with lyme.

Disease summaries

Lyme Disease:

Lyme bullseye rash: cdc.gov

• The most common tick-borne disease in our area, carried by the blacklegged tick
• Symptoms include fever, chills, headache, muscle pain, gastro symptoms, rash
• Symptoms typically appear 3-30 days after a bite
  • Diagnosis is usually symptom-based, including rash and tick exposure
  • Treatment is with antibiotics, generally doxycycline.

Ehrlichiosis:

• Transmitted by blacklegged and lone star ticks
• Symptoms include fever, chills, headache, muscle pain, gastro symptoms, rash
• Symptoms typically appear in 5-14 days
• Diagnosis is based on symptoms and blood tests.
• Treatment is with antibiotics, generally doxycycline.

Anaplasmosis:

• Transmitted by blacklegged, lone star and American dog ticks
• Symptoms include fever, chills, headache, gastro symptoms, 10% of victims get a rash
• Early symptoms can be mild, appearing in 1-5 days
• Diagnosis is based on symptoms and blood tests
• Treatment is with antibiotics, generally doxycycline.

Tularemia:

Tularemia ulcer: cdc.gov

• A relatively rare disease transmitted by blacklegged, lone star and American dog ticks as well as deer flies and contact with dead infected animals
• Can be contracted by bite, contact with infected animal, or bacterial entry via eyes, lungs or digestive system (eating/drinking).
• Similar symptoms to the above diseases. One embodiment includes a skin ulcer. Lymph node swelling is also common.
• Diagnosis based on symptoms, exposures, blood tests and cultures
• Treatment is with various antibiotics.

STARI: (Southern tick-associated rash illness)

Various STARI rashes
cdc.gov

• Transmitted by lone star tick bite
• Symptoms very similar to Lyme Disease including expanding bullseye rash
• Diagnosis based on symptoms and knowledge of tick bite.
• Treatment is with doxycycline, but there are still questions about need and effectiveness of this practice.

Rocky Mountain Spotted Fever

Rash from RMSF
cdc.gov

Rocky Mountain Spotted Fever — one of the most dangerous tick-borne illnesses — is one of several related diseases.  The CDC now reports Rocky Mountain Spotted Fever under a broad  category called Spotted Fever Rickettsiosis (SFR), which includes Rocky Mountain Spotted Fever, Rickettsia parkeri rickettsiosis, Pacific Coast tick fever, and rickettsialpox.

• Transmitted by the American dog tick
• Virginia is classified by the CDC in the high incidence group of states, although five states — North Carolina, Oklahoma, Arkansas, Tennessee, and Missouri — account for over 60% of SFR cases. In the eastern US, it is most common in NC and TN.
• Symptoms include fever, headache, nausea, vomiting, etc. Rash is common 2-4 days after bite.  It can be deadly unless treated promptly.
• Diagnosis is based on symptoms, tick exposure or bite knowledge and blood tests
• Doxycycline is the recommended antibiotic treatment.

This CDC website offers the latest information on ticks and tick-borne diseases as well as bite-avoidance and disease prevention techniques.

Red Meat Allergy:

The tick bite that causes a red meat allergy has been in the news, but is not yet on the CDC website. It is caused by a carbohydrate called alpha-gal, not normally present in humans, being injected into the human bloodstream. This causes an immune or allergic reaction to occur when alpha-gal is ingested by eating red meat products including beef, pork, lamb, venison, rabbit and some dairy products. The best hypothesis is that alpha-gal is delivered to the bloodstream by the lone star tick,and that it takes multiple bites to build the alpha-gal level enough to cause the allergic reaction when the victim eats a red meat product. Intensity of response varies, and it dissipates in some but not all sufferers. Treatment is to avoid red meat and to treat symptoms with antihistamines, or in extreme cases with epinephrine, as they occur. Severe cases carry epi-pens just in case.

Preventive Measures

Ticks prefer moist places with cover, like forest leaf litter, shaded forest edges, and tall grasses. Minimize risks when in these environments:

• Wear long pants, long sleeves and hat. Tuck pants into socks. Light colors make it easier to spot ticks on clothes.
• Spray exposed skin with a minimum 20%, preferably 30-40% DEET product or other EPA approved insect repellent, following directions, especially regarding application to babies and children.
• Treat clothes with permethrin or wear purchased permethrin treated garments, following application directions.
• Stay in the center of trails, avoid the litter at forest edge
• After outdoor events, wash and dry clothes. Ticks can survive a hot water wash but an hour in the dryer at high temp kills them.
• Do a careful tick check after being in a tick-friendly area. Be especially thorough in checking moist and hairy areas like head, shoulders, armpits and inner thighs. Do the check promptly. Data shows a significant reduction in disease transmission if ticks are removed within 24 hours of biting. In any case, earlier removal is better.
• Remove embedded ticks properly, with a tweezers, gripped as close as possible to the head to avoid squeezing any contents in the tick into your body.
• Kill the tick in rubbing alcohol and save it for a few months in case any symptoms develop. The type of tick affects disease possibilities and since early symptoms are similar across different afflictions, knowing the specific tick type helps in diagnosis.
• Work with your vet to treat pets with tick-repelling medications, and check pets and possible animal hosts frequently. There are effective pet based repellents available
• There is some data that shows a benefit from taking a single prophylactic dose of doxycycline to reduce chances of contracting lyme disease when black legged ticks are removed 36 or more hours after the bite and the medication is taken within 72 hours of removal. It may make sense to talk with your doctor about outfitting yourself with this medication in advance if you have a significant risk of being bitten.
• While most infections depend on symptoms to arise before testing is done or medications prescribed, if a significant rash develops, see your doctor immediately. This doesn’t include the small itchy red spot that often surrounds the bite. But a bullseye, multiple spotted rash or hives are meaningful and demand medical evaluation.

Reducing risks in yard and garden

Ticks like dark, moist places and dislike hot, dry environments. So to minimize attractive tick nesting on properties:

• Keep grass trimmed and clean leaf litter from under shrubs and trees
• Remove trash and clutter that can provide cover for carrier rodents and ticks
• Securely cover compost and trash bins to discourage wildlife entry into your yard
• Stack wood neatly and keep it dry to prevent rodent nesting

Lawn edge tick barrier
Photo: pinterest.com

• If the yard is fenced, keep the inside of the fence cleared and clean. If not fenced, a 3 foot wide wood chip or gravel transition zone between lawn and woods has been shown to provide a barrier to tick entry.  See photo above.
• Ticks don’t travel far on their own. They are transported by their hosts. For larva this usually means small rodents, like the white footed mouse. Nymphs may attach to small-to-medium size mammals. Minimizing nesting sites and hiding places for the hosts helps keep ticks out. The risk with adults that attach to deer is that they drop off after their meal to nest and lay eggs for next season.

Chemical Options for Outdoor Areas

There are a variety of synthetic and botanical acaracides (substances used to control ticks and mites) available for home spraying.

• Synthetic acaracides are usually second generation pyrethroids, derivatives of insect toxins found in the chrysanthemum. They include bifenthrin, cyfluthrin and other “…thrin” compounds. They are less harmful to humans than earlier chemicals, but are still toxic to aquatic life and should not be applied near ponds, streams or wetlands. They are toxic to bees, so avoid spraying open flowers and don’t spray on windy days when drift is likely. Bifenthrin is considered effective against ticks and a spray application lasts for 1-3 months.
• Botanicals, generally essential oil combinations, may include rosemary, geraniol, peppermint oil and others. Because they are classed as food grade, they don’t require EPA registration, but follow handling and application directions carefully. Tests have shown some oils to be nearly as effective as bifenthrin. Others may repel but not kill ticks, so it makes sense to investigate formulation and effects prior to use.
• A non-spray treatment is to create a barrier with granular deltamethrin. Studies using this acaricide, distributed with a hand spreader, showed excellent results in reducing black legged ticks in a barrier band around properties. And in addition, the arthropod population damaged initially by the application, recovered in a few weeks.
• Another device that has achieved tick control success in testing is the bait box. These are tamper-proof boxes that use a bait to draw mice inside where the mouse rubs against acaracide-soaked wicks, killing ticks while sparing the mouse. The acaracide used is fipronil, the active ingredient in many vet-prescribed tick repellents for pets. Boxes are placed 30-50 feet apart and replaced in spring and fall. They have demonstrated major reductions in both tick populations and percent of ticks infected over a two year period. They are commercially available.

• 4 Posters are deer feeding boxes that lure deer to a central corn stash inside the box. When
  

  4 Poster Deer Feeding Box. Photo courtesy of  Fairfax County

  the deer reach into the corn bin, their ears, heads and necks rub against rollers soaked in an acaracide. The acaricide is spread further during grooming. 4 Posters must be tended weekly by licensed operators. They are also expensive when considering the structure, the chemical and the corn costs. There is a recommended density for a defined coverage area and they are considered more appropriate for communities than individual properties. A two year study completed in Fairfax County in 2016 generated inconclusive results, although other trials have claimed encouraging success.

What about a Lyme vaccine?

Because Lyme disease claims the most sufferers, people often ask why there is no anti-lyme vaccine. In fact there was a vaccine developed in the 1990s and marketed by SmithKline Beecham, now Glaxo SmithKline. It was expensive, relatively short lived and was discontinued in 2002 due to a lack of demand. There are multiple efforts underway today to develop a new vaccine, including one, Valneva, developed by a European pharma company that started EPA fast track clinical trials in 2018. Something is likely coming, but there is nothing available yet.

Do ticks bring anything positive to the world?

You have to be a true believer to see benefits from the existence of ticks. They’ve been here doing what they do, and surviving, since the dinosaurs lived. If you believe in diversity and see predator-prey relationships as natural and healthy, it’s possible to rationalize a constructive role for them. And they do provide food for possums and guinea hens as well as other land and aquatic animals. But, most of us could live without them.

Nevertheless, they are here and we have to contend with them. By managing our property, our outdoor habits and our hygiene, it’s possible to coexist while maintaining our preferred lifestyles. I hope that this article is helpful in constructing your battle plan.

Sources:

https://www.cdc.gov/lyme/prev/natural-repellents.html 

“Rocky Mountain Spotted Fever: Epidemiology & Statistics,” https://www.cdc.gov/rmsf/stats/index.html

http://npic.orst.edu/         

http://www.vdh.virginia.gov/content/uploads/sites/12/2016/10/Brochure.pdf

https://content.ces.ncsu.edu/ticks-and-tick-borne-diseases

https://pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/ENTO/ento-282/ENTO-282.pdf

https://content.ces.ncsu.edu/insect-repellent-products

https://www.health.ny.gov/diseases/communicable/lyme/fact_sheet.htm

http://www.ct.gov/caes/lib/caes/documents/publications/fact_sheets/entomology/deer_&_ticks_fact_sheet.pdf

https://www.lymedisease.org/lyme-basics/ticks/about-ticks/

https://www.cdc.gov/lyme/prev/natural-repellents.html

http://www.ticksinmaine.com/tick-control/when-to-hire-a-pro

https://www.fairfaxcounty.gov/wildlife/sites/wildlife/files/assets/documents/pdf/fairfax-county-4-poster-study-executive-summary.pdf

http://twp.freehold.nj.us/ticks/professional/publications/images_publications/20074postertopical.pdf