CRITTERS: TICKS
© 2006 RogueTurtle.com
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Ticks belong to the class Arachnida, which includes spiders, scorpions, and mites. Ticks go through four life stages: egg, larvae, nymph, and adult. The larvae have six legs while the nymphs and the adults have eight. Ticks are divided into two families, "soft" ticks and "hard" ticks. The only source of nutrition that ticks use is the blood sucked from their hosts.
In the United States seven kinds of hard ticks and five kinds of soft ticks carry diseases Often these diseases are transmitted by the ticks saliva during feeding behavior. However, some diseases, such as tularemia, can enter through the skin if a person comes in contact with a crushed infected tick. In recent years, Lyme disease has become the most reported arthropod borne disease in the country. Many experts feel if it were not for AIDS, Lyme disease would be the number one infectious disease in the United States
The front part of a tick consists of the "head" area and the mouthparts. The mouthparts have a central structure, the hypostome, which is shaped like a blunt harpoon, flat on the top and curved on the bottom where many sharp barbs are located.
A tick pushes its hypostome into a hole in the skin of a host that has been made by sharp teeth in the front of the hypostome. The barbs anchor the tick to the skin and make it difficult to pull the tick out. Some ticks also produce a cement-like substance that helps anchor them to the host. Sharp teeth at the front of the hypostome cut blood vessels under the skin, causing the blood to form a pool. The tick then sucks this blood into its gut through the hypostome. To keep the blood from clotting, ticks inject saliva containing a kind of anticoagulant into the blood pool. The saliva may also contain disease organisms, such as Borrelia burgdorferi which cause Lyme disease.
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Most ticks will crawl to the tips of grasses, brush, leaves, or branches and wait. With their front legs outstretched, they will wait for a host to brush up against them. This behavior is called questing (see photo left). When the tick does come into contact with an animal, it will grab on and crawl to an appropriate area on the animal to feed.
The Western Black-Legged Tick is the vector of Lyme Disease in the western United States, while the Pacific Coast Tick carries Tularemia and is a suspected carrier of Rocky Mountain Spotted Fever and Colorado Tick Fever. The Brown Dog Tick (Rhipicephalus sanguineus) has evolved to live indoors and can be found living inside your home. Brown Dog Ticks do not usually feed on humans.
"Deer tick" is the term commonly used when referring to Ixodes dammini, the principal vector of Lyme disease in the Northeast. In some states, the same term is used when referring to nymphal lone star ticks which are commonly found in western and south central portions of the state. Lone star ticks are not considered to be a vector of Lyme disease, although they can transmit Rocky Mountain spotted fever.
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FIRST AID: The best way to remove an attached tick.
Using a fine-point tweezer, grasp the tick just behind the point of attachment and pull slowly and steadily until the tick is dislodged. Vaseline, matches and other alternate methods of removal should be avoided. Wash the bite area, apply antiseptic and cover with a band-aid.
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LYME DISEASE
Lyme disease is caused by the bacterium Borrelia burgdorferi and is transmitted to humans by the bite of infected blacklegged ticks. The disease affects humans and a wide range of animals including pets and livestock. Lyme disease manifests itself in many ways and if left untreated may progress through several stages. The disease is difficult to diagnose clinically because early symptoms often mimic the flu (i.e., fatigue, headache, stiffness or pain in neck, muscles or joints, fever, or swollen glands). The most definitive early symptom is a gradually expanding circular or oval-shaped red rash. This rash only develops in about 70% of infected individuals, however, and may be overlooked.
Persons who experience any of the above-mentioned symptoms after being bit by a tick (or having spent time in tick-infested areas), should consult a physician immediately. Lyme disease can be treated successfully in these early stages with antibiotics. As the disease progresses, it becomes more difficult to manage. Later symptoms of infection may include heart and neurological disorders, and arthritis.
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PREVENTION
Steps to prevent Lyme disease include using insect repellent, removing ticks promptly, landscaping, and integrated pest management. The ticks that transmit Lyme disease can occasionally transmit other tick-borne diseases as well. DEET repellent works against ticks.
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ROCKY MOUNTAIN SPOTTED FEVER
Rocky Mountain spotted fever has not received the media attention of Lyme disease, but is potentially more deadly. Although RMSF can be successfully treated with antibiotics, medical experts estimate that without treatment, 20% of those infected could die. Rocky Mountain spotted fever is the most severe and most frequently reported rickettsial illness in the United States. It also occurs in Mexico and in Central and South America.
The disease is caused by Rickettsia rickettsii, a species of bacteria that is spread to humans by ixodid (hard) ticks. Initial signs and symptoms of the disease include sudden onset of fever, headache, and muscle pain, followed by development of rash on about the second to fifth day (on the wrists and ankles) Later the rash spreads to other parts of the body. In most cases, the tick must be attached for at least a day for infection to occur. The disease can be difficult to diagnose in the early stages, and without prompt and appropriate treatment it can be fatal.
Left: Photo of a late-stage of RMSF showing the spotting on the legs and feet of the victim.
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TICK PREVENTION
It is always a wise idea to inspect children (and adults) daily for any hitch-hikers, but especially check for ticks. Animals should also be checked. Like monkeys, this grooming out of bugs is vital to your health. Use small tweezers to gently pull out any ticks found, regardless of their "name" or size. No tick is good news. Small children are the hardest to treat, because they don't want to stand still while the tick is removed.
Don't even think about trying the old "hot iron & the tick will back out" treatment...it DOES NOT WORK. The tick will die, and your victim will be burned, before the tick backs out. It is quite a common site for veteran campers to sit around the campfire at night checking each other's hair for the presence of ticks. Normally, you cannot feel them when they dig into your skin.
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