Ticks are small arachnids that can transmit various pathogens, posing health concerns. They are present in many environments, often attaching to humans and animals. Understanding the types of ticks found in a region, their habitats, and potential risks helps individuals minimize encounters and prevent tick-borne illnesses.
Tick Species Common to Oregon
Oregon hosts several tick species. The Western black-legged tick, Ixodes pacificus, is prominent in western Oregon and along the Columbia River at lower elevations. This tick is small, with adults being brown-black and nymphs being tiny. It is the only known carrier of Lyme disease in Oregon.
The Rocky Mountain wood tick, Dermacentor andersoni, is found at higher elevations, especially east of the Cascades. American dog ticks, Dermacentor variabilis, are common throughout Oregon, favoring open spaces and trails. The Pacific Coast tick, Dermacentor occidentalis, is mainly found along Oregon’s coast and some inland areas. While the American dog tick does not transmit Lyme disease, both the Rocky Mountain wood tick and the Pacific Coast tick can carry other pathogens.
Oregon’s Tick Habitats
Ticks in Oregon thrive in diverse environments, including areas with dense vegetation, tall grasses, and wooded landscapes. They are found in both urban and rural settings. Specific areas like Catherine Creek, Rogue River, and Dog Mountain are known for higher tick activity. Ticks perch on low branches of shrubs or tall grass, waiting to attach to passing hosts.
Tick activity in Oregon peaks from March through August, with spring and early summer being the most active periods. Ticks can be encountered year-round in milder parts of the state, and some species, like adult Ixodes ticks, are active during cooler months. Warmer winters have led to an earlier start to the tick season, allowing them to remain active later into the fall.
Diseases Carried by Ticks in Oregon
Lyme disease, caused by Borrelia burgdorferi, is the most frequently reported tick-borne illness in Oregon, with an average of 40 to 69 human cases reported annually. This disease is primarily transmitted by the Western black-legged tick. Symptoms can include a bull’s-eye rash, fever, fatigue, and headache. The rash, known as erythema migrans, appears 3-30 days after a bite. Untreated Lyme disease can lead to more severe joint, neurological, or cardiac issues.
Anaplasmosis is another tick-borne bacterial infection, transmitted by the Western black-legged tick. It can cause flu-like symptoms such as fever, chills, headache, and muscle aches. Although rare in Oregon, Colorado tick fever, a viral disease, is transmitted by the Rocky Mountain wood tick. Symptoms include a sudden fever, headache, and muscle pain. Other diseases, such as Rocky Mountain spotted fever and tularemia, also occur in Oregon, though cases are rare.
Protection and Safe Tick Removal
Protecting oneself from tick bites involves several practical steps, especially when spending time outdoors. Wearing long-sleeved shirts, long pants, and closed-toe shoes can help create a barrier against ticks. Tucking pant legs into socks or boots further minimizes skin exposure. Choosing light-colored clothing makes it easier to spot ticks that may have attached.
Using EPA-registered insect repellents containing active ingredients like DEET, picaridin, or permethrin on clothing and gear can deter ticks. After outdoor activities, performing thorough tick checks on oneself, children, and pets is important, focusing on areas like the scalp, armpits, groin, and behind the knees. Showering within two hours of coming indoors can help wash off unattached ticks. Tumble drying clothes on high heat for at least 10 minutes can effectively kill any ticks present.
Prompt and proper removal of an attached tick is important to reduce disease transmission. Use fine-tipped tweezers to grasp the tick as close to the skin’s surface as possible, ideally at its head or mouthparts. Pull steadily upward without twisting or jerking, as this can cause the mouthparts to break off. After removal, clean the bite area and hands with soap and water or rubbing alcohol, then dispose of the tick by placing it in a sealed container, wrapping it tightly in tape, or flushing it down the toilet. Monitor the bite area for any rash or flu-like symptoms for several weeks, and consult a healthcare provider if concerns arise.