Blood-Sucking Ticks and the Diseases They Carry

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    NEWSLETTERS

    Centers for Disease Control

    Lurking in the high grass, waiting in ambush in the tree branches, tiny little parasites live for one purpose - sucking blood.  You are right to be repulsed.

    But aside from being creepy, these crawlies are also carrying disease.

    "This year, Lyme disease has really burst on the scene," said Monte Skall, the executive director of National Capital Lyme Disease Association.

    Skall said that the number of cases of Lyme disease in the region doubled since 2008.  She said in Virginia, the number of cases jumped from 330 in 2008 to 908 the following year.

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    Knowing which ticks cause what symptoms can help you avoid potentially dangerous illnesses carried by these loathsome bugs.

    In the Washington metropolitan region, researchers have identified three major tick species, with another type recently discovered in northern Virginia. 

    The most common species is the American dog tick, followed by the lone star tick.  Both of these ticks are about 1/8 of an inch wide. Both look similar, but the lone star tick has a white mark on the center of its back.  The tick that carries Lyme disease is the black-legged tick, commonly referred to as the deer tick.  A full-grown deer tick is about half of the size of a dog tick.  Click on the photo gallery for images.

    How do ticks make you sick?  The eight-legged creatures feed on animal blood, often from deer, rodents, or birds.  Those creatures carry bacteria that the ticks ingest, which they can in turn pass on to humans.

    Dog ticks, the most commonly found tick in the region, can carry Rocky Mountain spotted fever.  The largest number of cases for spotted fever transmission occur between April and September.  One of the tell-tale signs of infection is a red rash, that starts on the hands and feet 3 days after a bite and spread across the body if left untreated.  Other symptoms are swollen lymph nodes, joint pain, and flu-like symptoms.  After being bitten, it only takes a victim 3 to 6 hours to catch the disease after a bite.  If left untreated, it can be fatal.

    Here's the good news: spotted fever also kills dog ticks, so a relatively low number of the parasites found on humans are actually carriers.  The Virginia Department of Health estimates 3 percent of dog ticks are carrying Rocky Mountain spotted fever.  Other ticks might also be carriers of spotted fever, but its highly uncommon.

    Human Monocytic Ehrlichiosis (HME), another disease that has been found in the region, takes 24 hours to get passed on to humans after the initial bite.  The high season for this disease runs between April and September, and its carried by deer ticks and lone star ticks.

    HME appears 7 to 10 days after getting bitten.  Symptoms include fever, headache, muscle aches,

    nausea, and lack of appetite.  HME can lead to a rash.  The disease affects white blood cells and the central nervous system, and it can cause a meningitis-like brain inflammation in some cases.

    Lyme disease is tricky because some symptoms may not develop at all, and other symptoms can be very subtle.  One of the most recognized symptoms of Lyme disease is a bulls-eye shaped rash, that can show up several days after the tick bite.  However, in nearly a third of the cases, that rash will not appear.  Left untreated, the disease can lead to a decrease of muscle tone on both sides of the face, heading aches, dizziness, and pain shifting between different joints.  In advanced cases, numbness and short term memory problems can develop.

    Monte Skall said that children age 5 to 9 are catching Lyme disease in the greatest numbers, because kids are more likely to be playing outside.  Skall also said that Lyme disease can sometimes go undiagnosed because people go to get tested too early - the human body will not start making antibodies that will yield a positive blood test until four weeks after an infection.

    What do you do if you discover a tick?

    One thing not to do is grab the tick by the body and let rip - that's a good way to leave the head, or its pincers, left stuck in your skin, which can still cause infection.  

    The Virginia Department of Health recommends you remove a tick using tweezers.  Gently ease the body out, taking care not to leave any parts of the tick under the skin.  They also suggest saving ticks you've removed in a vial of alcohol, so that if you do fall ill, the tick can be used for diagnostic purposes.

    All of these tick-borne illnesses are treatable, and outcomes can be good when treated early.  Skall said that people should not stop going outside, but they should take care to check themselves for ticks when coming back inside.