Ticks, Ticks, and more Ticks

It’s well into tick season and for many, getting outdoors means dealing with ticks.  Not only are they annoying little creepy-crawlies, they are also vectors for many different diseases.

According to the CDC, the following disease/tick species associations are notweworthy in the United States (they are not necessarily exclusive to these particular tick species and there are likely to be more diseases, too):

Anaplasmosis Ixodes scapularis (blacklegged tick)

Ixodes pacificus (western blacklegged tick)

Babesiosis Ixodes scapularis (blacklegged tick)
Ehrlichiosis Amblyomma americanum (lone star tick)
Lyme disease Ixodes scapularis (blacklegged tick)

Ixodes pacificus (western blacklegged tick)

Rickettsia parkeri (Rickettsiosis) Amblyomma maculatum (Gulf coast tick)
Rocky Mountain Spotted Fever (RMSF) Dermacentor variabilis (American dog tick)

Dermacentor andersoni (Rocky Mountain wood tick)

Rhipicephalus sangunineus (brown dog tick)

STARI (Southern Tick-Associated Rash Illness) Amblyomma americanum (lone star tick)
Tickborne relapsing fever (TRF) infected soft ticks (family: Argasidae)
Tularemia Dermacentor variabilis (American dog tick)

Dermacentor andersoni (Rocky Mountain wood tick)

Amblyomma americanum (lone star tick)

364D Rickettsiosis Dermacentor occidentalis (Pacific coast tick)

Each species of tick has a unique geographic distribution.

View Larger Map

This does not mean that the diseases associated with different tick species will occur throughout that tick’s range. Many factors affect which diseases an individual tick will transmit. Latitude affects the feeding habits of blacklegged ticks, so they are less likely to bite humans in the southern portion of their range. Since many diseases rely heavily on a host animal population, this is also a major factor affecting disease distribution. This map is general, and only a guide. It is summarized from the individual maps on the CDC’s geographic distribution page.

The CDC has a fairly generalized page up describing tick life cycles and such. It’s worthwhile if you are new to these ideas, but each species will have variations on the details regarding seasonality, host specificity, and the like. If you are wondering about a specific species’ life cycle, you are going to have to dig up the details elsewhere.

Now that you’ve read all you can stomach about different tick species and the diseases they can potentially carry (you DID read EVERYTHING at all of the links I sent you to, right?), now we have to figure out what to do about them.

There are misconceptions out there about ticks. Notably, some folks still believe that ticks “jump” out at you from the brush. Nope. Watch one try to crawl around on the ground sometime after you pick it off. They’re pretty ungainly creatures. Do you think something like this is capable of anything resembling jumping? No. They’re not. What they do is climb onto trailside vegetation and reach their legs out. They’ve got hooks on their legs that work great for grabbing hair (and fabric). When an animal passes by, their feet grab on and they go for a ride. There is no jumping or hunting or seeking you out. Understanding this, we can try to prevent them from making a meal out of us.

Because of the way they hunt, repellents aren’t really the best choice by themselves. Many manufacturers claim that DEET repels ticks, but I’m not convinced. If you really want a repellent, then I would go with the 3M Ultrathon lotion. You really don’t need a higher concentration than 30% to get maximum effectiveness, and Ultrathon is 34.4%. Since DEET can be toxic if overused, I like the time released formula that works longer to help avoid over-application. Really the only thing a higher concentration gets you is a longer effectiveness, not increased repellency. The time released formula accomplishes that without raising the concentration.

One word of note – I know DEET/sunscreen combination formulas are popular, and I know there is a 3M Ultrathon product that offers this. Don’t do it. Insect repellent and sunscreen have different application frequencies. You will either OD yourself on one in order to keep the other effective, or you’ll end up suffering to avoid overapplying the other. And it’s usually the sunscreen that needs more frequent application. That means you either apply too much DEET to keep sunscreen efficacy or you lose sunscreen efficacy while the DEET continues to work. Do yourself a favor, research sunscreens and carry a small amount of a good formula separately from your bug juice.

Now since I don’t think repellent works well on ticks at all, you have to use another method. My primary method of avoiding tick problems is to wear long pants. The majority of the time I’ve found ticks, they’ve been on my legs. So protecting your legs on the trail is number one. If the ticks are especially bad, this might also mean some gaiters over the cuffs of your pants or tucking your pants into your socks.

Obviously, wearing long pants on a bicycle when it’s summertime is impractical at minimum and could even be dangerous due to the risk of overheating. In this situation, repellent is really the only preventive measure you can take on bare skin.

The one chemical that does work well against ticks is permethrin. You can get it from several companies as an aerosol or a soak. You can get the soak in concentrate form, also, and dilute it. Generally speaking, the aerosol cans only have enough for two sets of clothes. If you use a lot of it, the concentrate may be the way to go.

Be careful with permethrin. Let me say this again (in bold and underlined), BE CAREFUL WITH PERMETHRIN. It is toxic when wet. If you are using the soak method, do it outside and wear thick rubber gloves. If you are spraying, still use it outside, but as long as you don’t point the spray upwind, you should be okay. It is especially toxic to cats (when wet). Do not handle treated clothing until they’re dry. Best to let them dry in the sun. Once dry, the treatment should last several weeks and through several washings.

rayestrella at the backpacker.com forums posted an excellent writeup about diluting a permethrin concentrate. Note that he recommends diluting the solution to about 1.5% before soaking. With a little math, you can work out how to dilute any concentrate to 1.5%. Take the stuff I linked to earlier for example (my link is not an endorsement, it is purely an example). It is 36.8%. This kind of dilution gets expressed in terms of volume per volume. Let’s say we want to mix a 5 gal bucket of solution to treat a pile of clothing. So, our 36.8% permethrin concentrate has .368 gal of pure permethrin per gallon of solvent. To figure out how much of the concentrate to put in our 5 gal bucket, we multiply .368 gal/gal by 5 gal. We get to cancel some units and the result is 1.84 gal of concentrate. Measure that out into the bucket. You can just finish filling the bucket with water since it has a known volume, or if you’re working in a larger container just subtract 1.84 from 5 which means you’ll be needing to add 3.16 gal of water to your bucket if you’re meticulous.

Once your clothing dries out, you’ll be all set for several weeks and/or washings on your gear. I see a lot of claims that permethrin is a repellent and it’ll keep the mosquitoes away and so you can spray it on your tent or your bug net or whatever to keep flying bugs away. It might be a mild repellent, but it’s not worth using for mosquitoes. I use it exclusively for ticks. Treating some of your gear with it might be a good idea, because you don’t necessarily want a tick to hitch a ride on your pack and get a free ride to your neck where it can hide in your hair.

Now that we’ve been through prevention, we need to address additional methods. First thing’s first, no matter what preventive methods you’re using, you need to ritualize the tick check. If you have a significant other, he or she can be a huge help with checking intimate areas. If you have a friend who can check behind your ears, that’s a great help. Blacklegged (deer) ticks can be TINY (especially the nymphs) and you may not feel them yourself until they are engorged. Check the crooks of your joints where blood runs close to the surface, anyplace there’s hair that a tick can hide, and near waistbands, cuffs, and collars of your clothing.

If you find one, hopefully you’ve caught it before it bites. Get it off and crush it. Hard ticks can be seriously difficult to kill. I usually need to crush it between two rocks. My fingernails are often not enough. If it has bitten, you’ll need to get it off. If you’re lucky, you’ll be able to feel it bite. I have only been bitten by lone star ticks so I can’t say about other species. But every time I’ve been bitten by a lone star tick, I felt a little pinch. If it’s that soon, its head won’t be embedded in your skin and getting it off should be fairly easy. If the tick has embedded, you’ll need to be careful.

A few things NOT to do:

burn it with a match (it will vomit in your skin, possibly transmitting some disease it was carrying)
suffocate it with nail polish (same deal)
rip it off (you want to avoid breaking the head off, leaving it behind. this can cause an infection)

If you can pry it off and get the head out intact, you’re in good shape. A handy little tool everyone should keep in their first aid kit is a Tick Key. It’s small, it’s easy to use, it’s lightweight. You can even put it on your keychain (if you keychain isn’t full of bulky alarm system keyfobs already).

Hopefully in reading this, I’ve helped to arm you with some good information about protecting yourself, your family, and your pets from ticks and the diseases they can carry.

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