From the Guidelines
Lyme disease in the northeastern United States is primarily carried by the blacklegged tick (Ixodes scapularis), also commonly known as the deer tick, which is the main vector responsible for transmitting Borrelia burgdorferi, the bacterium that causes Lyme disease, to humans. The life cycle of these ticks involves three stages: larva, nymph, and adult, with the nymph stage posing the greatest risk for Lyme disease transmission because they are active during spring and summer when people spend more time outdoors, and their small size makes them easy to miss during tick checks 1. Deer ticks require blood meals at each life stage and can acquire the Lyme disease bacterium by feeding on infected animals, particularly white-footed mice. Some key points to consider:
- The prevalence of B. burgdorferi in nymphal I. scapularis ticks commonly ranges between 20% and 40% in areas of endemicity in the Northeastern and upper Midwestern United States 1.
- I. pacificus ticks (the vector for Lyme disease in the western United States) have a much lower infection rate with B. burgdorferi (0%–14%) 1.
- The risk of developing Lyme disease after a tick bite can be estimated based on the duration of tick attachment, with a higher risk associated with longer attachment times 1. To protect yourself from tick bites, use insect repellent containing DEET or permethrin, wear long sleeves and pants when in wooded or grassy areas, perform thorough tick checks after being outdoors, and remove any attached ticks promptly with fine-tipped tweezers 1.
From the Research
Ticks Carrying Lyme Disease in the Northeast
- The primary tick species responsible for transmitting Lyme disease in the Northeast is the blacklegged tick (Ixodes scapularis) 2, 3, 4.
- Ixodes scapularis is a vector of several human pathogens, including those causing Lyme disease, anaplasmosis, babesiosis, and others 3.
- The geographic range of Ixodes scapularis has increased in recent years, leading to a higher risk of Lyme disease transmission in the Northeast 5, 6, 4.
Distribution of Ixodes scapularis
- Ixodes scapularis has been found in various counties across the Northeast, including Ohio, Michigan, and other states 5, 6, 4.
- The tick's distribution is often associated with wooded, brushy, and grassy areas, where it can feed on small mammals and birds 6.
- Climate and environmental factors, such as temperature and humidity, can influence the tick's population dynamics and distribution 4.
Lyme Disease Risk
- The risk of Lyme disease transmission is higher in areas with established populations of Ixodes scapularis 2, 3, 4.
- Human activities, such as hiking, camping, and gardening, can increase the risk of exposure to infected ticks 2.
- Preventive measures, such as wearing protective clothing, using tick repellents, and performing frequent body checks, can reduce the risk of Lyme disease transmission 2.