*This information is provided by the Center for Disease Control as part of the public domain. Avoiding Ticks Reducing exposure to ticks is the best defense against Lyme disease, Rocky Mountain spotted fever, and other tickborne infections. There are several approaches you and your family can use to prevent and control Lyme disease: On People On Pets In the Yard A Lyme disease vaccine is no longer available. The vaccine manufacturer discontinued production in 2002, citing insufficient consumer demand. Protection provided by this vaccine diminishes over time. Therefore, if you received the Lyme disease vaccine before 2002, you are probably no longer protected against Lyme disease. Tick Removal If you find a tick attached to your skin, there's no need to panic. There are several tick removal devices on the market, but a plain set of fine-tipped tweezers will remove a tick quite effectively. How to remove a tick 1. Use fine-tipped tweezers to grasp the tick as close to the skin's surface as possible. 2. Pull upward with steady, even pressure. Don't twist or jerk the tick; this can cause the mouth-parts to break off and remain in the skin. If this happens, remove the mouth-parts with tweezers. If you are unable to remove the mouth easily with clean tweezers, leave it alone and let the skin heal. 3. After removing the tick, thoroughly clean the bite area and your hands with rubbing alcohol, an iodine scrub, or soap and water. 4. Dispose of a live tick by submersing it in alcohol, placing it in a sealed bag/container, wrapping it tightly in tape, or flushing it down the toilet. Never crush a tick with your fingers. Avoid folklore remedies such as "painting" the tick with nail polish or petroleum jelly, or using heat to make the tick detach from the skin. Your goal is to remove the tick as quickly as possible--not waiting for it to detach. Created 8/26/2014 Page 1 of 12
Follow-up If you develop a rash or fever within several weeks of removing a tick, see your doctor. Be sure to tell the doctor about your recent tick bite, when the bite occurred, and where you most likely acquired the tick. Geographic Distribution In this section American dog tick Blacklegged tick Brown dog tick Gulf Coast tick Lone star tick Rocky Mountain wood tick Western blacklegged tick While adult ticks are the easiest to identify by species, immature stages of ticks may also transmit some pathogens. In addition, male and female ticks of the same species may look different. Of the many different tick species found throughout the world, only a select few bite and transmit disease to humans. These maps provide general insight into the expected distribution of ticks that cause disease in the contiguous United States. Populations of ticks may be found outside noted areas. Naturally occurring populations of the ticks described below do not occur in Alaska, however, the brown dog tick is endemic in Hawaii. Created 8/26/2014 Page 2 of 12
American dog tick (Dermacentor variabilis) American dog tick (Dermacentor variabilis) is the most commonly identified species responsible for transmitting Rickettsia rickettsii, which causes Rocky Mountain spotted fever in humans. The American dog tick can also transmit tularemia. This tick is widely distributed east of the Rocky Mountains and also occurs in limited areas on the Pacific Coast. D. variabilis larvae and nymphs feed on small rodents. Dogs and medium-sized mammals are the preferred hosts of adult D. variabilis, although it feeds readily on other large mammals, including humans. Approximate distribution of the American Dog tick. Created 8/26/2014 Page 3 of 12
Blacklegged tick (Ixodes scapularis) The blacklegged tick (Ixodes scapularis), commonly known as a "deer tick", can transmit the organisms responsible for anaplasmosis, babesiosis, and Lyme disease. This tick is widely distributed in the northeastern and upper midwestern United States. I. scapularis larvae and nymphs feed on small mammals and birds, while adults feed on larger mammals and will bite humans on occasion. It is important to note that the pathogen that causes Lyme disease is maintained by wild rodent and other small mammal reservoirs, and is not transmitted everywhere that the blacklegged tick lives. In some regions, particularly in the southern U.S., the tick has very different feeding habits that make it an unlikely vector in the spread of human disease. Approximate distribution of the Blacklegged tick. Created 8/26/2014 Page 4 of 12
Brown dog tick (Rhipicephalus sanguineus) The brown dog tick (Rhipicephalus sanguineus) has recently been identified as a reservoir of R. rickettsii, causing Rocky Mountain spotted fever, in the southwestern U.S. and along the U.S-Mexico border. Brown dog ticks are found throughout the U.S. and the world. Dogs are the primary host for the brown dog tick for each of its life stages, although the tick may also bite humans or other mammals. Approximate distribution of the Brown Dog tick. Gulf Coast tick (Amblyomma maculatum) The Gulf Coast tick resides in coastal areas of the United States along the Atlantic coast and the Gulf of Mexico. The Gulf Coast tick can transmit Rickettsia parkeri rickettsiosis, a form of spotted fever. A. maculatum larvae and nymphs feed on birds and small rodents, while adult ticks feed on deer and other wildlife. Adult ticks have been associated with transmission of R. parkeri to humans. Created 8/26/2014 Page 5 of 12
Approximate distribution of the Gulf Coast tick. Lone star tick (Amblyomma americanum) The lone star tick (Amblyomma americanum) transmits Ehrlichia chaffeensis and Ehrlichia ewingii, causing human ehrlichiosis, tularemia, and STARI. The lone star tick is primarily found in the southeastern and eastern United States. White-tailed deer are a major host of lone star ticks and appear to represent one natural reservoir for E. chaffeensis. A. americanum larvae and nymphs feed on birds and deer. Both nymphal and adult ticks may be associated with the transmission of pathogens to humans. Approximate distribution of the Lone Star tick. Created 8/26/2014 Page 6 of 12
Rocky Mountain wood tick (Dermacentor andersoni) Rocky Mountain wood tick (Dermacentor andersoni) can transmitrocky Mountain spotted fever and tularemia to humans. This tick is found in the Rocky Mountain states. Adult ticks feed primarily on large mammals. Larvae and nymphs feed on small rodents. Adult ticks are primarily associated with pathogen transmission to humans. Approximate distribution of the Rocky Mountain Wood tick. Created 8/26/2014 Page 7 of 12
Western blacklegged tick (Ixodes pacificus) The western blacklegged tick (Ixodes pacificus) can transmit the organisms responsible for causing anaplasmosis and Lyme disease in humans. Wild rodents and other mammals are likely reservoirs of these pathogens. This tick is distributed along the Pacific coast of the United States. Larvae and nymphs feed on birds and small rodents, while adult ticks feed on deer and other mammals. Both adult and nymphal ticks are known to transmit disease to humans. Approximate distribution of the Western Blacklegged tick. Created 8/26/2014 Page 8 of 12
Life cycle of Hard Ticks that Spread Disease In this section: How ticks survive How ticks find their hosts How ticks spread disease How ticks survive Most ticks go through four life stages: egg, six-legged larva, eight-legged nymph, and adult. After hatching from the eggs, ticks must eat blood at every stage to survive. Ticks that require this many hosts can take up to 3 years to complete their full life cycle, and most will die because they don't find a host for their next feeding. Relative sizes of several ticks at different life stages. Created 8/26/2014 Page 9 of 12
Ticks can feed on mammals, birds, reptiles, and amphibians. Most ticks prefer to have a different host animal at each stage of their life, as shown below: This diagram shows the life cycle of blacklegged ticks that can transmit anaplasmosis, babesiosis, and Lyme disease. How ticks find their hosts Ticks find their hosts by detecting animals breath and body odors, or by sensing body heat, moisture, and vibrations. Some species can even recognize a shadow. In addition, ticks pick a place to wait by identifying wellused paths. Then they wait for a host, resting on the tips of grasses and shrubs. Ticks can't fly or jump, but many tick species wait in a position known as "questing". While questing, ticks hold onto leaves and grass by their third and fourth pair of legs. They hold the first pair of legs outstretched, waiting to climb on to the host. When a host brushes the spot where a tick is waiting, it quickly climbs aboard. Some ticks will attach quickly and others will wander, looking for places like the ear, or other areas where the skin is thinner. Created 8/26/2014 Page 10 of 12
How ticks spread disease Ticks transmit pathogens that cause disease through the process of feeding. Depending on the tick species and its stage of life, preparing to feed can take from 10 minutes to 2 hours. When the tick finds a feeding spot, it grasps the skin and cuts into the surface. The tick then inserts its feeding tube. Many species also secrete a cement-like substance that keeps them firmly attached during the meal. The feeding tube can have barbs which help keep the tick in place. Ticks also can secrete small amounts of saliva with anesthetic properties so that the animal or person can't feel that the tick has attached itself. If the tick is in a sheltered spot, it can go unnoticed. A tick will suck the blood slowly for several days. If the host animal has a bloodborne infection, the tick will ingest the pathogens with the blood. Small amounts of saliva from the tick may also enter the skin of the host animal during the feeding process. If the tick contains a pathogen, the organism may be transmitted to the host animal in this way. After feeding, most ticks will drop off and prepare for the next life stage. At its next feeding, it can then transmit an acquired disease to the new host. Tickborne Diseases of the U.S. In the United States, some ticks carry pathogens that can cause human disease, including: Anaplasmosis is transmitted to humans by tick bites primarily from the blacklegged tick (Ixodes scapularis) in the northeastern and upper midwestern U.S. and the western blacklegged tick (Ixodes pacificus) along the Pacific coast. Babesiosis is caused by microscopic parasites that infect red blood cells. Most human cases of babesiosis in the U.S. are caused by Babesia microti. Babesia microti is transmitted by the blacklegged tick (Ixodes scapularis) and is found primarily in the northeast and upper midwest. Borrelia miyamotoi infection has recently been described as a cause of illness in the U.S. It is transmitted by the blacklegged tick (Ixodes scapularis) and has a range similar to that of Lyme disease. Colorado tick fever [PDF - 21 pages] is caused by a virus transmitted by the Rocky Mountain wood tick (Dermacentor andersoni). It occurs in the the Rocky Mountain states at elevations of 4,000 to 10,500 feet. Ehrlichiosis is transmitted to humans by the lone star tick (Ambylomma americanum), found primarily in the southcentral and eastern U.S. Heartland virus infection has been identified in eight patients in Missouri and Tennessee as of March 2014. Studies suggest that Lone Star ticks may transmit the virus. It is unknown if the virus may be found in other areas of the U.S. Lyme disease is transmitted by the blacklegged tick (Ixodes scapularis) in the northeastern U.S. and upper midwestern U.S. and the western blacklegged tick (Ixodes pacificus) along the Pacific coast. Powassan disease is transmitted by the blacklegged tick (Ixodes scapularis) and the groundhog tick (Ixodes cookei). Cases have been reported primarily from northeastern states and the Great Lakes region. Created 8/26/2014 Page 11 of 12
Rickettsia parkeri rickettsiosis is transmitted to humans by the Gulf Coast tick (Amblyomma maculatum). Rocky Mountain spotted fever (RMSF) is transmitted by the American dog tick (Dermacentor variabilis), Rocky Mountain wood tick (Dermacentor andersoni), and the brown dog tick (Rhipicephalus sangunineus) in the U.S. The brown dog tick and other tick species are associated with RMSF in Central and South America. STARI (Southern tick-associated rash illness) is transmitted via bites from the lone star tick (Ambylomma americanum), found in the southeastern and eastern U.S. Tickborne relapsing fever (TBRF) is transmitted to humans through the bite of infected soft ticks. TBRF has been reported in 15 states: Arizona, California, Colorado, Idaho, Kansas, Montana, Nevada, New Mexico, Ohio, Oklahoma, Oregon, Texas, Utah, Washington, and Wyoming and is associated with sleeping in rustic cabins and vacation homes. Tularemia is transmitted to humans by the dog tick (Dermacentor variabilis), the wood tick (Dermacentor andersoni), and the lone star tick (Amblyomma americanum). Tularemia occurs throughout the U.S. 364D rickettsiosis (Rickettsia phillipi, proposed) is transmitted to humans by the Pacific Coast tick (Dermacentor occidentalis ticks). This is a new disease that has been found in California. Created 8/26/2014 Page 12 of 12