Lyme disease, also known as Lyme borreliosis, is an infectious disease caused by bacteria of the Borrelia type which is transmitted to humans through a bite from an infected black-legged tick, commonly known as a deer tick.
Lyme disease, being a tick-borne disease, is the most common disease spread by ticks in the Northern Hemisphere. It is estimated to affect 300,000 people a year in the United States and 65,000 people a year in Europe. Infections are most common in the spring and early summer.
Lyme disease is transmitted to humans by the bite of infected ticks of the genus Ixodes. The chances you might get Lyme disease from a tick bite depend on the kind of tick, where you were when the bite occurred, and how long the tick was attached to you. Usually, a black-legged tick must be attached for 36 to 48 hours before the bacteria can spread. The tick becomes infected after feeding on infected deer or mice. In North America, Borrelia burgdorferi and Borrelia mayonii are the cause. In Europe and Asia, the bacteria Borrelia afzelii and Borrelia garinii are also causes of the disease. The disease does not appear to be transmissible between people, by other animals, or through food.
Signs and Symptoms
The most common sign of infection is an expanding area of redness on the skin, known as erythema migrans, that begins at the site of a tick bite about a week after it has occurred.
About 20% to 30% of Lyme rashes have a “bull's-eye” appearance (concentric circles around a centre point), but most are round and uniformly red and at least 5 centimetres (about 2 inches) across.
The rash expands gradually over a period of days and can grow to about 12 inches across. It may feel warm to the touch, but it rarely itches or is painful, and it can appear on any part of the body.
Approximately 25–50% of infected people do not develop a rash. Other early symptoms may include:
muscle and joint pain
swollen lymph nodes
If left untreated, symptoms can progress and may include:
severe headache with neck stiffness
rashes on other areas of the body
arthritis with severe joint pain and swelling, particularly in the knees
loss of muscle tone or “drooping” on one or both sides of the face.
heart palpitation or an irregular heartbeat
inflammation of the brain and spinal cord
shooting pains, numbness, or tingling in the hands or feet
When to see a doctor
The rash is a pretty good indication that you may have been bitten. Take a photo of the rash and see your doctor. At this stage of the illness, treatment with antibiotics will probably be successful.
If you don’t have the telltale rash but have a summer flu which includes fatigue, fever, headache but no respiratory symptoms like a cough, you may want to talk to your doctor.
Lyme disease is diagnosed based on:
signs and symptoms
a history of possible exposure to infected black-legged ticks
and possibly testing for specific antibodies in the blood
While blood tests are often negative in the early stages of the disease, they are helpful if used correctly and performed with validated methods.
How do you know if you’ve been bitten?
Given that the ticks are the size of a poppy seed, you’ve got to have pretty good eyes. It is advised that if you have been walking in the woods, in tall grass, or working in the garden, check your skin afterward, ideally in the shower or bath. That way, you have removed your clothes, which may carry ticks, too.
Tick bites are usually difficult to notice also because the bites are painless as they burrow deep into the skin. Though, some people have an allergic reaction to ticks, so they will notice a bite right away.
Treatment for Lyme Disease
Lyme disease is best treated in the early stages. Early treatment is a simple 14 to 21 day course of oral antibiotics to eliminate all traces of infection. Medications used to treat Lyme disease include:
doxycycline for adults and children older than 8 years old
cefuroxime and amoxicillin for adults, younger children, and women who are nursing or breastfeeding
Persistent or chronic Lyme disease is treated with intravenous antibiotics for a period of 14 to 21 days. Though this treatment eliminates the infection, your symptoms improve more slowly.
Despite appropriate treatment, about 10 to 20% of people develop joint pains, memory problems, and feel tired for at least six months.
It’s unknown why symptoms, like joint pain, continue after the bacteria have been destroyed. Some doctors believe that persistent symptoms occur in people who are prone to autoimmune disease.
A Lyme vaccine was marketed in the US between 1998 and 2002; it was withdrawn from the market due to poor sales, originally due to lack of reimbursement by insurance companies and then due to rumours about adverse effects. Research is ongoing to develop new vaccines.
How to Prevent Lyme Disease
Lyme disease prevention mostly involves decreasing your risk of experiencing a tick bite. Take the following steps to prevent tick bites:
Cover up when outdoors in areas with high risk like in wooded or grassy areas. Wear shoes, trousers tucked into your socks, a long-sleeved shirt, a hat and gloves. Try to stick to trails and avoid walking through low bushes and long grass. Keep your dog on a leash.
Bathe or shower within two hours of coming indoors.
Wash clothes in hot water, and tumble dry clothes on high heat for at least 10 minutes to kill any ticks.
Make your yard unfriendly to ticks by clearing wooded areas, keeping underbrush to a minimum, and putting woodpiles in areas with lots of sun.
Discourage deer by fencing your yard.
Wear a tick repellent on your skin and clothing that has DEET, lemon oil, or eucalyptus. For even more protection, use the chemical permethrin on clothing and camping gear. Parents should apply repellent to their children, avoiding their hands, eyes and mouth. Keep in mind that chemical repellents can be toxic, so follow directions carefully. It shouldn’t be used on children under the age of 3.
Be vigilant. Check your children, pets, and yourself for ticks. Don’t assume you can’t be infected again; people can get Lyme disease more than once.
Treat pets with anti-tick treatment.
Remove ticks quickly and correctly with tweezers. Apply the tweezers near the head or the mouth and pull gently. Check to be certain that all tick parts have been removed and take a photo in case you need to show a doctor. You’re not likely to get infected if you remove the tick within 24hours.
Clean the bite and your hands with rubbing alcohol.
Dispose of ticks in alcohol, a sealed container, or down the toilet.
Contact your doctor whenever a tick bites you or your loved ones.
Lyme Disease in Animals
Lyme disease affects humans as well as animals. Dogs, horses, and cattle can become infected.
Pets with the disease may not show signs for up to five months, according to the American Veterinary Medical Association.Symptoms in animals may include fever, loss of appetite, and decreased appetite. Animals also get antibiotics for treatment.
Since animals can also spread the disease by carrying infected ticks, pet owners should always examine any animal coming indoors after time spent in wooded or grassy areas.