Friday, July 8, 2016

Lyme Disease

Lyme disease is caused by the bacterium Borrelia burgdorferi and 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. Lyme disease is diagnosed based on symptoms, physical findings (e.g., rash), and the possibility of exposure to infected ticks.  Laboratory testing is helpful if used correctly and performed with validated methods. Most cases of Lyme disease can be treated successfully with a few weeks of antibiotics. Steps toprevent Lyme disease include using insect repellent, removing ticks promptly, applying pesticides, and reducing tick habitat. The ticks that transmit Lyme disease can occasionally transmit other tickborne diseases as well.(1)

credit/source:  http://www.cdc.gov/lyme/index.html


Transmission


The Lyme disease bacterium, Borrelia burgdorferi, is spread through the bite of infected ticks. The blacklegged tick (or deer tick, Ixodes scapularis) spreads the disease in the northeastern, mid-Atlantic, and north-central United States. The western blacklegged tick (Ixodes pacificus) spreads the disease on the Pacific Coast.
Ticks can attach to any part of the human body but are often found in hard-to-see areas such as the groin, armpits, and scalp. In most cases, the tick must be attached for 36 to 48 hours or more before the Lyme disease bacterium can be transmitted.
Most humans are infected through the bites of immature ticks called nymphs. Nymphs are tiny (less than 2 mm) and difficult to see; they feed during the spring and summer months. Adult ticks can also transmit Lyme disease bacteria, but they are much larger and are more likely to be discovered and removed before they have had time to transmit the bacteria. Adult Ixodes ticks are most active during the cooler months of the year.

  • 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.
  • Lyme disease acquired during pregnancy may lead to infection of the placenta and possible stillbirth; however, no negative effects on the fetus have been found when the mother receives appropriate antibiotic treatment. There are no reports of Lyme disease transmission from breast milk.
  • Although no cases of Lyme disease have been linked to blood transfusion, scientists have found that the Lyme disease bacteria can live in blood that is stored for donation. Individuals being treated for Lyme disease with an antibiotic should not donate blood. Individuals who have completed antibiotic treatment for Lyme disease may be considered as potential blood donors. Information on the current criteria for blood donation is available on the Red Cross website.
  • Although dogs and cats can get Lyme disease, there is no evidence that they spread the disease directly to their owners. However, pets can bring infected ticks into your home or yard. Consider protecting your pet, and possibly yourself, through the use of tick control products for animals.
  • You will not get Lyme disease from eating venison or squirrel meat, but in keeping with general food safety principles, always cook meat thoroughly. Note that hunting and dressing deer or squirrels may bring you into close contact with infected ticks.
  • There is no credible evidence that Lyme disease can be transmitted through air, food, water, or from the bites of mosquitoes, flies, fleas, or lice.
  • Ticks not known to transmit Lyme disease include Lone star ticks (Amblyomma americanum), the American dog tick (Dermacentor variabilis), the Rocky Mountain wood tick (Dermacentor andersoni), and the brown dog tick (Rhipicephalus sanguineus).
credit/source: http://www.cdc.gov/lyme/transmission/index.html


If you find a tick attached to your skin, there's no need to panic. Several tick removal devices are available on the market, but a plain set of fine-tipped tweezers will remove a tick 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.

   clipart style image showing the proper removal of a tick using a pair of tweezers

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.

Helpful Hint

 icon of a tickAvoid 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--do not wait for it to detach.
http://www.cdc.gov/lyme/removal/index.html
TESTING OF TICKS

Signs and Symptoms of Untreated Lyme Disease

Untreated Lyme disease can produce a wide range of symptoms, depending on the stage of infection. These include fever, rash, facial paralysis, and arthritis.  Seek medical attention if you observe any of these symptoms and have had a tick bite, live in an area known for Lyme disease, or have recently traveled to an area where Lyme disease occurs.

medical illustration of Erythema migrans, medical illustration of Bell's Palsy, and medical illustration of an arthritic knee

Early Signs and Symptoms (3 to 30 days after tick bite)

  • Fever, chills, headache, fatigue, muscle and joint aches, and swollen lymph nodes
  • Erythema migrans (EM) rash:
    • Occurs in approximately 70 to 80 percent of infected persons
    • Begins at the site of a tick bite after a delay of 3 to 30 days (average is about 7 days)
    • Expands gradually over a period of days reaching up to 12 inches or more (30 cm) across
    • May feel warm to the touch but is rarely itchy or painful
    • Sometimes clears as it enlarges, resulting in a target or “bull's-eye” appearance
    • May appear on any area of the body
    • See examples of EM rashes

Later Signs and Symptoms (days to months after tick bite)

  • Severe headaches and neck stiffness
  • Additional EM rashes on other areas of the body
  • Arthritis with severe joint pain and swelling, particularly the knees and other large joints.
  • Facial or Bell's palsy (loss of muscle tone or droop on one or both sides of the face)
  • Intermittent pain in tendons, muscles, joints, and bones
  • Heart palpitations or an irregular heart beat (Lyme carditis)
  • Episodes of dizziness or shortness of breath
  • Inflammation of the brain and spinal cord
  • Nerve pain
  • Shooting pains, numbness, or tingling in the hands or feet
  • Problems with short-term memory
credit/source: http://www.cdc.gov/lyme/signs_symptoms/index.html

Treatment

Patients treated with appropriate antibiotics in the early stages of Lyme disease usually recover rapidly and completely. Antibiotics commonly used for oral treatment include doxycycline, amoxicillin, or cefuroxime axetil. Patients with certain neurological or cardiac forms of illness may require intravenous treatment with drugs such as ceftriaxone or penicillin.

credit/sourcehttp://www.cdc.gov/lyme/treatment/index.html


Additional pictures to show AFTER Tick Bite
A tick latches onto skin, where it then feeds on blood.
photo credit: www.medicinenet.com/


Lyme disease initially affects the skin, causing an expanding reddish rash similar to a target or bull's-eye.
photo credit:  www.medicinenet.com/


Relative sizes of blacklegged ticks at different life stages


Relative sizes of several ticks at different life stages. In general, adult ticks are approximately the size of a sesame seed and nymphal ticks are approximately the size of a poppy seed.
photo credit:www.cdc.gov/lyme/
In general, adult ticks are approximately the size of a sesame seed and nymphal ticks are approximately the size of a poppy seed