DEP’s Tick Surveillance and Testing Program is responsible for conducting statewide active tick surveillance to determine the distribution, prevalence, and expansion of tick populations throughout the Commonwealth. In addition, the Vector Management Laboratory identifies, enumerates, and prepares ticks for pathogen testing. After the ticks are prepared, they are tested for pathogens that can impact human health. The pathogen list includes: Borrelia burgdorferi (causative agent of Lyme Disease), Anaplasma phagocytophilum (causative agent of Anaplasmosis), Babesia microti (causative agent of Babesiosis), Deer Tick Virus (Powassan Virus Lineage II), Borrelia miyamotoi (causative agent of Hard Tick Relapsing Fever), and Borrelia mayonii (causative agent of Lyme Disease).
Due to their ability to transmit Lyme Disease and other tickborne illnesses the Program focuses mainly on Ixodes scapularis (Blacklegged or Deer Tick. Funding is provided to local mosquito control programs to conduct tick surveillance from April through August. During this time, DEP and county staff focus on the nymphal stage of the Blacklegged tick, however, other ticks are surveyed for in their respective habitats. Other ticks that are frequently collected include Dermacentor variabilis (American Dog tick), Amblyomma americanum (Lonestar tick), Haemaphysalis longicornis (Asian Longhorned tick), and Amblyomma maculatum (Gulf Coast tick). In the fall and winter DEP staff collect the adult stage of Blacklegged ticks. All Blacklegged ticks are collected in the field by dragging, sent to the lab for positive identification, and processed for molecular testing of pathogens.
Step 1: DEP and county biologists collect ticks using 1 m2 felt drag. Holly Chapman (DEP) conducts dragging to collect adult Blacklegged ticks.
Step 2: DEP Taxonomist Denny Keen identifies, enumerates, and prepares ticks to be tested. On average there are 18,400 ticks identified annually by the Vector Management Laboratory.
Step 3: DEP’s Vector Management Molecular Laboratory annually tests ~8,000 individual ticks for the presence of multiple pathogens of human health importance.
Life Cycle
Most of the tick species in Pennsylvania have a three-host life cycle in which they feed on a different individual host at each active life stage (larva, nymph, and adult). Upon hatching from the egg, six-legged larvae seek out and begin feeding on their first host, usually small mammals such as mice. It is typically during the larval stage that the tick becomes infected with disease-causing organisms. Once fully engorged, the larval tick drops from its host and molts to a nymph. The nymph will then locate and feed on its second host, release, and molt into an adult. The adult tick feeds upon a third and final host. Once mated and fully engorged, the adult female tick will deposit a single batch of several thousand eggs into the leaf litter and die. The entire life cycle takes place over the course of one to three years depending on the species of tick.
Behavior
Ticks do not jump, fly or drop from trees onto their hosts. They typically use a passive behavior known as questing to seek out their hosts. When questing, a tick will perch at the end of a piece of vegetation with front legs extended and simply latch on to a suitable host as it passes by. This behavior is intensified in response to certain stimuli, such as carbon dioxide, body heat, vibrations, and other bodily cues. Some tick species are more aggressive in response to these stimuli and will travel several meters to locate a host.
Once the tick is on a host it may immediately attach and start feeding or it may wander around before settling on a spot. Feeding may last several days or up to several weeks depending on the species. Females utilize these extended feedings, while males only take small occasional blood meals, if they feed at all. Males will remain on the host for extended periods in order to find a mate.
Habitat
Tick habitat can vary depending on the tick species’ preferred host. Some species are found primarily in the burrows, dens, or nests of their host, while others may be found in a variety of settings. Ticks are highly susceptible to desiccation (drying out) and thus need habitat with relatively high humidity to survive. In general, ticks tend to be found in wooded areas, tall grass or brush, the edges where woods and lawn meet, in the leaf litter, under ground-cover plants, and around stone walls and woodpiles where small mammals live. Within this habitat, ticks generally quest in vegetation at the height of their preferred hosts. Larvae tend to remain close to the ground where they are more likely to locate small mammals. Nymphs and adults typically move higher into the vegetation but generally stay below waist-level. Identifying and eliminating tick habitat around one’s property is an excellent way to reduce exposure to ticks.
Staff drag edge habitat for adult Ixodes scapularis
Staff drag grass for the presence of Haemaphysalis longicornis
Some habitats can be preferred by several species of ticks including the one above where you could find Ixodes scapularis and Dermacentor variabilis.
Disease Transmission
Ticks can carry and transmit many types of bacteria, parasites, and viruses that can make people sick. Tickborne illnesses have been on the rise over the past decade. According to the CDC, Lyme Disease alone was diagnosed and treated in approximately 315,000 patients annually from 2010-2018. Ticks pick up pathogens when biting an infected host, usually small rodents such as the White-footed Mouse. After becoming infected and molting to the next life stage, the tick will look for another host. After the subsequent bite, pathogen transmission will occur.
Lyme Disease: Borrelia burgdorferi, Borrelia mayonii
Lyme disease is the most common vector-borne disease in the United States. Lyme disease is caused by the bacterium Borrelia burgdorferi and rarely, Borrelia mayonii. It is transmitted to humans through the bite of infected Blacklegged ticks. Typical symptoms include fever, headache, fatigue, and a characteristic skin rash called erythema migrans. If left untreated, infection can spread to joints, the heart, and the nervous system.
Borrelia mayonii are a type of bacteria recently found in North America that can cause Lyme disease. These bacteria are different from the three types of bacteria that cause most cases of Lyme disease worldwide.
Based on limited information, illness caused by B. mayonii appears similar to that caused by B. burgdorferi, but with a few differences. Like B. burgdorferi, B. mayonii causes fever, headache, rash, and neck pain in the days after infection and can cause arthritis after a few weeks of illness. Unlike B. burgdorferi, B. mayonii can also cause nausea and vomiting; large, widespread rashes; and a higher concentration of bacteria in the blood.
Human Granulocytic Anaplasmosis: Anaplasma phagocytophilum
Anaplasmosis is a disease caused by the bacterium Anaplasma phagocytophilum. These bacteria are spread to people by tick bites primarily from the Blacklegged tick.
People with anaplasmosis will often have fever, headache, chills, and muscle aches.
Babesiosis: Babesia microti
Babesiosis is caused by microscopic parasites that infect red blood cells and are spread by the Blacklegged Tick in PA. Babesia infection can range from asymptomatic to life threatening. Most infections cause fever, chills, sweats, and fatigue. Although many people who are infected with Babesia do not have symptoms, for those who do effective treatment is available.
Deer Tick Virus: (Powassan Virus Lineage II)
Powassan virus is spread to people by the bite of an infected tick. Although still rare, the number of reported cases of people sick from Powassan virus has increased in recent years. Most cases in the United States occur in the northeast and Great Lakes regions from late spring through mid-fall when ticks are most active. There are no vaccines to prevent or medicines to treat Powassan virus disease. Reduce your risk of infection from Powassan virus by avoiding ticks.
Powassan virus can be transmitted in as little as 15 minutes after tick attachment.
Hard Tick Relapsing Fever: Borrelia miyamotoi
Borrelia miyamotoi is a type of spiral-shaped bacteria that is closely related to the bacteria that cause tickborne relapsing fever (TBRF). It is transmitted by the bite of an infected Blacklegged tick in PA. Sign and symptoms include fever, chills, severe headache, and fatigue.
Ehrlichiosis: Ehrlichia chaffeensis, E. ewingii, or E. muris
Ehrlichiosis is the general name used to describe diseases caused by the bacteria in the United States. These bacteria are spread to people primarily through the bite of infected ticks including the lone star tick (Amblyomma americanum) and the blacklegged tick (Ixodes scapularis).
People with ehrlichiosis will often have fever, chills, headache, muscle aches, and sometimes upset stomach. Doxycycline is the treatment of choice for adults and children of all ages with ehrlichiosis.
Spotted fever group rickettsioses (spotted fevers): Rickettsia rickettsii, R. parkeri
Rocky Mountain Spotted Fever (RMSF) is a bacteria most often transmitted by the bite of the American Dog Tick in PA. RMSF can be rapidly fatal if not treated within the first 5 days after symptoms occur.
Rickettsia parkeri Rickettsiosis is a bacteria that can transmitted by the Gulf Coast Tick in PA and is closely related to RMSF. They have similar signs and symptoms, including fever, headache, and rash. Differing from RMSF there typically appears an inoculation eschar at the site of the tick attachment.
Clothing
When outdoors it is important to protect yourself from ticks. Wearing light colored clothing makes it easier to see any ticks that may be crawling on your clothing. Tucking your shirt into your pants and your pants into your socks can help keep ticks on top of your clothing and off your skin, this will increase the likelihood of you seeing the tick before it can attach. Using repellents that can be sprayed onto your clothing, like permethrin, will repel and kill any ticks that you come into contact with. The heat from a dryer can also kill ticks that may be crawling on your outdoor clothes.
Tick Checks
Checking yourself for ticks after being outdoors is important to reduce the risk of tickborne disease. The longer a tick is attached the more likely it is to transmit pathogens it may be carrying. Ticks like moist, dark, thin-skinned areas to attach. The following are important areas to focus on when conducting a tick check.
- Hairline
- Behind ears
- Armpits
- Waistband
- Between legs
- Behind knees
Repellants & Insecticides
Use an EPA approved insect repellent for tick prevention.
DEET is a repellant used for ticks and mosquitoes. It can be sprayed directly on skin and/or clothing to help keep ticks away.
- Spray on yourself and clothing, repels ticks
- 20% to 30% DEET most effective
- DEET by itself tested between 85%-89% effective at repelling ticks.
Permethrin is an insecticide that is sprayed on your clothes only. It will kill ticks on contact.
- Spray on clothing off body, let dry, kills ticks with contact
- Good for up to 6 washes
- Picardin
- Oil of Lemon Eucalyptus
Tick removal
- Locate where the tick is attached. Use fine tipped tweezers or a tick key for removal. It is important to remove a tick as soon as possible, the longer a tick is attached increases the likelihood of contracting a tickborne disease.
- Grasp the tick at its head or as close to the skin surface as possible.
- Pull upward with steady and even pressure. Do not twist or jerk the tick.
- After thoroughly removing the tick, clean the bite area and your hands with rubbing alcohol or soap and water.
Do no use household remedies such as burning the ticks, Vaseline, or using nail polish. Always remove the tick as soon as possible.
Habitat management: Landcsaping techniques
The following are a few things that can be done around the home to minimize ticks and tick host habitat:
- Keep grass trim, long grass provides questing habitat for ticks
- Rake leaves, leaves provide habitat for nymphal and larval ticks
- Cut back edge habitat, edge habitat hanging into your yard is a great place for ticks to quest
- Increase sunlight, ticks dry out easily so high sunlight areas will deter ticks
- Remove clutter, cluttered areas provide habitat for mice and other small mammals that act as a host
- Keep playground equipment, decks, and patios away from yard edges and trees
- Stack wood neatly and away from the home
- Mulch barriers provide a barrier between your yard and the woods, they also serve as a mental reminder that past the area is tick risky habitat
- Discourage unwelcome animals from entering your yard by constructing fences
*Anaplasma phagocytophilum infection rates do not differentiate between deer and human variant.
These are the results for the most recent Ixodes scapularis nymph statewide survey that was completed in the spring and summer of 2024 delineated by PA Department of Health Regions The total number of specimens collected in the region are denoted by the “n.” Individual ticks were tested for the presence of 3 pathogens that impact human health, including Borrelia burgdoferi, Anaplasma phagocytophilum, and Babesia microti.
Archived Maps
The Tick Program staff does not respond to personal property complaints concerning ticks. However, if you would like more information or to express concerns, see contact information below. Concerns will be addressed by conveying educational materials related to habitat management to reduce ticks on your property and personal protection measures that you can take to reduce the likelihood of being bitten by ticks.
Contact: RA-EPTickInfo@pa.gov