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Lyme Disease



Lyme disease is the most common vector-borne disease in the United States with approximately 30,000 new cases reported each year.

Lyme disease gets its name from a small coastal town in Connecticut called Lyme. In 1975, a woman brought an unusual cluster of pediatric arthritis cases to the attention of Yale researchers. In 1977, the Yale researchers identified and named the clusters “Lyme arthritis." In 1979, the name was changed to "Lyme disease," when additional symptoms such as neurological problems and severe fatigue were linked to the disease. In 1982 the cause of the disease was discovered by Dr. Willy Burgdorfer. Dr. Burgdorfer published a paper on the infectious agent of Lyme disease and earned the right to have his name placed on the Lyme disease spirochete now known as Borrelia burgdorferi.

BLAST Program

Image with words Blast Lyme Disease.

The BLAST Program was adapted by Delaware Public Health from the Ridgefield Connecticut Program to raise awareness of the most effective Lyme disease prevention practices, as well as to educate the community about the early signs and symptoms of Lyme and other tick-borne diseases to promote timely diagnosis and treatment.



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Lyme Disease Awareness



Found a tick?           

Upload a photo of the tick and get information on the tick species! Knowing what species of tick has attached to you, a family member, or a pet will help determine whether you may be at risk for a tick-borne disease.

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Tick Bite Bot



Delaware Statistics

Delaware is among the top 10 states with the highest incidence rates in the United States. 


2022 385 253 64 68 64
2021 354 250 40 64 65
2020 355 249 43 161 35.97
2019 641 437 86 136 65.83
2018 520 302 87 131 53.77

1Cases/100,000 based on population data from the US Census Bureau

*As per the CDC Case Classification Criteria-Please note that the CDC case classification for Lyme Disease changed in 2022


The Lyme disease bacterium, Borrelia burgdorferi, is transmitted to animals and humans through the bite of an infected blacklegged or deer tick. Immature ticks are very tiny and can be difficult to see which can increase the possibility of undetected tick exposures. The ticks that transmit Lyme disease can occasionally transmit other tickborne diseases as well like Powassan virus, babesiosis, and anaplasmosis


There is no evidence that Lyme disease is transmitted from person-to-person. For example, a person cannot get infected from touching, kissing or having sex with a person who has Lyme disease. Humans most often acquire Lyme disease in the spring and summer months when they enjoy outdoor activities.

Image of the bull's eye Rash at tick bite site.



The Lyme disease bacterium can infect several parts of the body which can cause different symptoms at different times. Symptoms of Lyme disease can be nonspecific and may resemble other diseases. If you think you have Lyme disease it is important that you contact your healthcare provider. Follow this link for a printable poster of common symptoms.


Image of the Blast symptoms poster.

Early Symptoms:

  • Rash – Lyme disease is frequently characterized by an expanding red rash, commonly referred to as a bull’s - eye rash. Rashes can occur anywhere on the body, and vary in size and shape. The rash can be warm to the touch, but usually not painful or itchy. Not all patients will develop the characteristic rash.
  • Fever and/or chills
  • Fatigue
  • Muscle and joint aches
  • Headache

Untreated infections can lead to a variety of symptoms, some of which can be very serious and debilitating. These symptoms can include:

  • Severe joint pain and swelling (usually large joints, particularly the knees)
  • Loss of muscle tone on one or both sides of the face (called, “Bell’s palsy”)
  • Heart palpitations and dizziness
  • Severe headaches and neck stiffness due to meningitis
  • Neurological problems (i.e., numbness or tingling in the hands or feet, problems with concentration and short term memory)
  • The Lyme disease bacterium, Borrelia burgdorferi, is transmitted to animals and humans through the bite of an infected blacklegged or deer tick.► The Lyme disease bacterium, Borrelia burgdorferi, or sometimes Borrelia mayonii, is transmitted to animals and humans through the bite of an infected blacklegged or deer tick. 


Diagnosis is based on symptoms, physical findings (i.e., bull’s – eye rash, facial palsy or arthritis) and a history of possible exposure to ticks. Validated laboratory tests are available to assist the clinician with the diagnosis. Laboratory testing is not recommended or necessary when a patient develops the characteristic bulls-eye rash.

Lyme disease can be difficult to diagnose. Not all patients with Lyme disease will develop the characteristic bulls-eye rash and tick exposures often go undetected.



Most cases of Lyme disease can be cured with a few weeks of antibiotics taken by mouth. Depending on symptoms, some patients may require a second course of antibiotic therapy. Patients with certain neurological or cardiac forms of illness may require intravenous (IV) antibiotics.

A small percentage of patients with Lyme disease have symptoms that last months to years after treatment with antibiotics. These symptoms can include muscle and joint pains, arthritis, cognitive defects, sleep disturbance, and fatigue. The cause of these symptoms is not known. There is some evidence that they result from an autoimmune response, in which a person’s immune system continues to respond even after the infection has been cleared.

Surveillance and Reporting

The Centers for Disease Control and Prevention (CDC) initiated Lyme disease surveillance in the United States in 1982. Lyme disease became a reportable condition in Delaware in 1989 under the Regulations for the Control of Communicable and other Disease Conditions which made Lyme disease, as well as many other diseases and conditions, reportable to the Bureau of Epidemiology in Delaware Division of Public Health (DPH).

In turn, DPH submits weekly data regarding all reportable diseases to CDC. CDC is then able to publish weekly reports and annual summaries in the Morbidity and Mortality Weekly Report (MMWR). The data in the weekly MMWR are provisional, based on weekly reports to CDC by state health departments.

For surveillance purposes, a case of Lyme disease in Delaware is defined according to the CDC/Council of State and Territorial Epidemiologists (CSTE) case definition.

The Bureau of Epidemiology in DPH utilizes the Delaware Electronic Reporting and Surveillance System (DERSS) to automatically receive positive laboratory results from major commercial laboratories on all reportable diseases, including Lyme disease. Additionally, all acute care hospitals in Delaware submit reportable disease reports electronically into DERSS.


Personal protection:

  • Know where to expect ticks -- blacklegged ticks live in moist and humid environments, particularly in or near wooded or grassy areas. You may come in contact with ticks during outdoor activities around your home or when walking through vegetation such as leaf litter or shrubs.
  • Wear light-colored clothing to allow you to see ticks crawling on your clothing.
  • When possible, wear long sleeves and long pants. Tuck your pant legs into your socks so that ticks cannot crawl up inside of your pant legs.
  • Apply tick repellents. Repellents containing permethrin can be sprayed on boots and clothing and will last for several days. Repellents containing DEET can be applied to the skin but will last only a few hours before reapplication is necessary. Use insect repellent containing less than 50 percent DEET for adults. Use repellent containing less than 30 percent DEET on children. The American Academy of Pediatrics (AAP) Committee on Environmental Health updated their recommendation for use of DEET products on children in 2003, citing: "Insect repellents containing DEET (N,N-diethyl-m-toluamide, also known as N,N-diethyl-3-methylbenzamide) with a concentration of 10 percent appear to be as safe as products with a concentration of 30 percent when used according to the directions on the product labels." AAP recommends that repellents with DEET should not be used on infants less than 2 months old. Use this search tool to help you choose the repellent product that is right for you. Insect repellent guide in both English and Spanish
  • Upon return from outdoor activities in potentially tick-infested areas, search your body for ticks. Take special care to check under the arms, in and around the ears, inside the belly button, behind the knees, between the legs, in and around all head and body hair, and around the waist.
  • Check children for ticks, especially in the hair. Additionally, ticks may be carried into the household on clothing and pets.

Image of a tick being removed with tweezers.

Tick Removal:

  • Use fine-tipped tweezers or shield your fingers with a tissue, paper towel or rubber gloves. Avoid removing ticks with bare hands whenever possible.
  • Grasp the tick close to the skin surface and pull upward with steady, even pressure.
  • Do not squeeze, crush, or puncture the body of the tick since its fluids (saliva, body fluids, gut contents) may contain infectious germs.
  • After removing the tick, cleanse the site with an antiseptic or soap and water, and wash your hands.
  • The use of home remedies such as petroleum jelly or hot matches for tick removal are not recommended. These methods do not work.
  • View/print our "Blast Lyme Disease" poster

Landscape Management:

  • Keep grass mowed.
  • Remove leaf litter, brush and tall weeds from around the home and the edge of your lawn.
  • Use plantings that do not attract deer or exclude deer through various types of fencing. Deer are the main food source for adult ticks.
  • Move firewood, birdhouses and feeders away from the home.
  • Create a 3-foot or wider wood chip, mulch or gravel barrier between your lawn and woods.
  • Modify your landscaping to create "tick-safe zones ".

To learn more about Lyme Disease:

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Office of Infectious Disease Epidemiology

24/7 Emergency Contact Number: 1-888-295-5156

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