Bad as a Bullet: Tick and Mosquito-Borne Diseases, by D.K., DVM

We have SCUBA friends from Canada who do a lot of camping, and one year the wife came down with a debilitating illness that put her out of work for many months.  The medical system there did not make it easy to consult a specialist, especially one familiar with arthropod-borne diseases.  She showed all the symptoms of Lyme disease, including weakness, fever, sore joints, lethargy, headaches, and muscle aches.  Plus she had been exposed to ticks while camping.  She suffered for over a year before she slowly recovered.  Though it was never confirmed to be a tick-borne illness, odds are it was.

Another friend, a lieutenant colonel in the Marine Corps Reserves who lives in Connecticut, came down with fever and joint pain and was diagnosed with three tick-borne diseases, which put him out of work for a year and a half.  It’s not unusual for a tick to carry more than one of these nasty infections at a time.

Ticks and mosquitoes can put you out of action just as easily as a bullet.  In fact, throughout history disease has caused more casualties in war than any other factor, including combat.  When you’re fighting for survival in the field, your hygiene is reduced, your stress is high, and your immune system is depressed.  You may not have time to check yourself for ticks every day, but you certainly should.  If you served in Vietnam, you lost a lot of blood to mosquitoes over there, and were exposed to malaria as well.  In the Middle East its sand flies.

There are seven major species of ticks found in the continental United States that can carry disease.  It’s not important to be able to tell them apart, just know what a tick looks like.  I start seeing ticks on dogs in the spring, and usually have a collection of a couple dozen by the end of May.  People bring their dogs in for a “lump,” or what they think may be a skin tag.  Ticks are always on the surface of the skin, and do not burrow into or under the skin.  Just their mouthparts penetrate.

An adult tick is about 3/16 to ¼” long, oval, and has eight legs.  An engorged tick full of blood can be ½” long.  Photos of live ticks in the wild generally show the tick on a leaf or blade of grass with one or two of its front legs reaching out.  You could say they’re thumbing for a ride, because when an animal or man passes by, a small hook at the end of the leg grabs onto hairs or fabric. 

Now, they don’t have their leg out all the time, but just like a hitchhiker, they put it out when something stimulates them.  Carbon dioxide from your breath is the number one trigger that they sense, and it may also be the reason they move to the head area once they’re on board.  There are more capillaries close to the surface of the skin on the head and neck, too, for them to access.

Vibrations in the ground as you tromp along the trail can be felt on the end of that blade of grass by the tick, and even air movement or body heat may be a factor for them to reach out and say, “Hey!”  Although a tick may feed anywhere on the body, they do tend to migrate up (on humans) or forward on animals.  We may find them attached at our waistline or armpits, but more commonly in the hairline on the neck or behind the ears.  Adult ticks are usually felt when you run your hands through your hair, but odds are you will never feel the bite.

Ticks produce a potent anesthetic in their saliva that numbs the skin where their mouthparts penetrate.  They actually grab or glue to a small fold of skin and won’t let go.  When you remove a tick, it often comes away with that tiny piece of skin in its mouth.  Another ingredient of the saliva is an anticoagulant to keep the blood flowing until the female tick is filled to the max and falls off, ready to lay eggs.

Adult ticks are usually easily noticeable and readily found, but the smaller nymph stage is equally infective and can be quite small and hard to find.  The blacklegged tick (deer tick), the primary transmitter of Lyme disease, has a nymph stage that is so tiny it will fit inside the “O” in “ONE DIME” (pull out a dime and see).  It would indeed take a fine-toothed comb to find one on a dog, and could easily go unnoticed for days on a human.

We test dogs every year for heart worms (mosquito-borne), and the test we use also checks for Lyme, anaplasmosis, and ehrlichiosis from ticks.  The incidence in Ohio for Lyme is one out of 172, anaplasmosis is one out of 300, and ehrlichiosis is one out of 324.  (2012, www.dogsandticks.com)  The study that came up with these figures is far from accurate, however, because only a fraction of dog owners have their pets checked for heartworm every year, let alone have them on heartworm preventives.  So the actual occurrence of these diseases is undoubtedly higher.  The point is, where there’s ticks, there is also disease.

While the “system” is working, you can use 20% or stronger DEET (N, N-diethyl-m-toluamide) on exposed skin to repel ticks and mosquitoes.  Some clothing comes treated with permethrin that is effective tor numerous washings, or you can buy permethrin treatment kits to do your own clothes.  Eventually, you will run out of these consumables in a TEOTWAWKI situation, and you will have to fall back on daily full-body inspections for ticks, which may have additional benefits if you are checking each other.

Some sources recommend wearing light-colored clothing, which one theory states ticks don’t like, or more likely because they are easier to spot crawling on light colors.  If you’re wearing camo, this won’t work so well.  Tuck your pant legs into your boots.  I’ve always preferred over-the-calf Thorlo® anti-fatigue or combat boot socks with drawstring cuff BDU pants, in-the-boot combination.  With everything tucked in, including t-shirts into underpants, it’s more likely a tick that gets through the barriers will end up on the neck and head, making it easier to find.

There are several neat little devices out there to remove ticks, but plain old tweezers or forceps work well, too.  These tick tools are designed to grasp the head of the tick near the skin, so that you don’t squeeze the body (and supposedly squirt juices into your skin).  Steady, gentle traction will pull the tick off your skin.  Do not jerk it or burn it with a match or cigarette.  More likely you will get burned also.  Remember, ticks do not burrow, so they’ll be obviously above the skin but attached to it.

A simple tick tool you can make requires a stout plastic teaspoon and a Xacto® “razor saw.”   Cut a shallow-angled “V” in the tip of the spoon bowl, about ½” deep.  Slide the bowl channel under the tick and lift upward with gentle traction, and the tick will come away.  Now you can burn it or crush it.  Wash the bite area with soap and water, betadine or alcohol, and wash your hands, too, if you handled the tick.

Mosquitoes are also bad as a bullet.  Worldwide they kill more people than anything else (malaria), yet before Rachel Carson’s “Silent Spring” brought about the ban on DDT, it was on the decline.  Millions have died since the ban, and continue to drop from malaria.  More than any other product to prevent malaria (and other mosquito-borne diseases), the mosquito net stands supreme.  Costing anywhere from $5 to $100, you can get a travel-size bed canopy net www.longroad.com or military surplus nets that are suspended above your cot or ground cover.  There are many choices.

Mosquitoes are most active at dusk and dawn, but in wooded or tropical areas they bite all day and night, and prefer the shade and humidity.  They are attracted to carbon dioxide, perspiration, body odors, and body heat.  Researchers found that mosquitoes do have clothing color preferences, too.  They seem attracted more to dark colors, and prefer blue.  Unlike the tick, you’ll usually feel the initial bite of a mosquito, but then its saliva numbs the wound and you won’t notice until its tank is full.

In the USA mosquitoes carry various encephalitis viruses, including Eastern, Western, and Venezuelan Equine Encephalitis Viruses and West Nile Virus.  Case fatality rates run from 0.3% to as high as 60%.  With little medical supportive care available after a collapse, more will die.  Up to 50% of survivors have continuing problems with neurologic aftereffects.  You don’t want this, so take prevention seriously. 

Remove or drain all standing water containers (old tires, cans) from your habitat area.  Check roof gutters also for standing water, and if you have water catch barrels cover them with screen to keep mosquitoes from breeding in the water.  Adding goldfish to ponds helps to keep the mosquito larvae population under control.  While the federal and state governments are under control, it is illegal to use oil, soap, or other products on standing water that “suffocate” the larvae.  And in most areas you need to have a license to apply any chemical to the environment for insect control.  You don’t want to poison your own environment.

Repellants are great while you have them, but keeping your skin and head covered is the best protection.  Head nets are available, and the army surplus nets with a thin metal suspension ring work well.  There are natural repellants that work fairly well, too, using essential oils, but again they will eventually run out.  Avoiding mosquito havens, like swampy and dark areas, will reduce your attacks.

The Centers for Disease Control and Prevention have a good web site for information on ticks and mosquitoes www.cdc.gov/ticks/diseases/index.html, and it’s relatively easy to prevent these illnesses.  Just watch out for them and check yourself every day, as well as do what you can to repel them.

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