Infectious Diseases A to Z – Lyme Disease

With this new column, Elite Healthcare will compile an index of various infectious diseases, with occasional highlights of emerging conditions.

Lyme disease

General definition and information:

An infection that causes illness in more than 300,000 people per year, Lyme disease is caused by the bacterium Borrelia burgdorferi spread to humans through the bite of infected ticks. According to the Centers for Disease Control and Prevention (CDC), reported Lyme disease cases have increased steadily over the past 25 years, although improved prevention methods are one of CDC’s priorities.

Typical symptoms include fever, headache, fatigue, and a characteristic skin rash that resembles a bull’s eye target known as erythema migrans (EM). The infection can spread to joints, the heart, and the nervous system if left untreated. Although most cases can be treated successfully with a few weeks of antibiotics, untreated conditions can lead to serious consequences.

Early signs and symptoms can begin as soon as 3 days after being bitten and last up to about 30 days. Fever, chills, headache, fatigue, muscle and joint aches, and swollen lymph nodes will likely be present. The EM rash occurs in approximately 70-80% of all cases, according to the CDC, expands gradually, and can reach more than 12 in size.

Later signs and symptoms, which may take months to surface, include severe headaches and neck stiffness, additional EM rashes, arthritis with severe joint pain and swelling, facial palsy (loss of muscle tone or drooping of the face), tendon and muscle pain, heart palpitations or irregular heart beat, dizziness or shortness of breath, inflammation of the brain and spinal cord, nerve pain, and problems with short-term memory.

Causes & Modes of Transmission:

According to the CDC, the blacklegged tick (deer tick) is responsible for the spread of the disease. The arachnids will most likely attach themselves to the groin area, armpits, and scalp, making them hard to detect after they cling to a human host. Transmission of Lyme disease typically requires at least 36 hours before the bacterium can cause the infection,1 and most ticks that cause infection will be less than 2 mm in size.1 Because ticks can secrete a cement-like substance to keep them firmly attached to their host and small amounts of saliva with anesthetic properties, those who have ticks burrowed into their skin often cannot feel the tick. Ticks will suck blood slowly for several days and can ingest pathogens that can then infect other humans if they attach to multiple hosts.

According to the CDC, scientists have found that Lyme disease bacteria can live in blood that is stored for donation, although no evidence exists of the disease being transmittable by blood transfusion. Individuals being treated for Lyme disease with an antibiotic should not donate blood,1 although those who have completed antibiotic treatment may be considered as eligible donors. Lyme disease is diagnosed based on signs and symptoms as well as laboratory blood tests.

Treatment Strategies:

Appropriate antibiotic treatment in the early stages of the disease typically leads to rapid and complete recovery, according to the CDC. Antibiotics commonly used for oral treatment include doxycycline, amoxicillin, or cefuroxime axetil. People with certain neurological or cardiac forms of illness may require intravenous treatment with antibiotics, such as ceftriaxone or penicillin.2 The CDC offers a list of suggested treatment regimens for early intervention.

Some patients may experience post-treatment Lyme disease syndrome, the cause of which is unknown, according to the CDC. People who received prolonged courses of antibiotics do not necessarily fare better long term than patients treated with placebo, according to studies funded by the National Institutes of Health. Long-term antibiotic or alternative treatments for Lyme disease have been associated with serious complications,2 and healthcare providers are advised to consider associated risks.3

Prevention Parameters:

Avoiding ticks will be the best prevention method. However, when this is not easily accomplished, quick detection and removal of a tick (ideally within 24 hours) will greatly reduce one’s chances of acquiring Lyme disease, and the longer the tick is attached to the host the greater the risk of disease. Healthcare providers can share some tips for members of their community to increase their chances of avoiding tick bites:

  • Ticks live in grassy, brushy, or wooded areas, and many people have ticks in their own yards. Clothing and gear can be treated with products containing 0.5% permethrin and remain protective through several washings. Environmental Protection Agency-registered insect repellents are advised, although insect repellents should not be used on babies younger than 2 months old (avoid products containing Oil of Lemon Eucalyptus and para-menthane-diol on children under 3 years old).
  • When tick exposure has been likely, check clothing for ticks when returning home. Tumble dry clothes on high heat for 10 minutes to kill potential ticks on dry clothing. (If clothes are damp, additional time may be needed.) Ticks can ride into the home on clothing and pets, then attach to a person later. Shower soon after being outdoors and conduct a full-body tick check. (Use a handheld or full-length mirror to view all parts of the body.)

Additionally, CDC researchers have reportedly discovered that a naturally occurring compound known as nootkatone that’s found in, among other things, grapefruit, can kill or repel ticks and insects. CDC officials are reportedly working with an exclusively licensed partner to evaluate and develop next-generation pest prevention and control products. The CDC also claims that it is evaluating the effectiveness of permethrin-treated clothing as a prevention method. Results from a pilot study are available4 and additional studies are ongoing. CDC and collaborators have also pioneered research in the use of rodent-targeted treatments, including bait boxes that treat mice and other rodents for ticks in an effort to upset the transmission cycle of Lyme disease. Funding from the CDC has also enabled researchers to develop an oral vaccine for rodents that can reduce the transmission of Lyme disease in nature, according to officials who said evaluation of this product is ongoing.

References

  1. Lyme disease transmission. CDC. 2019. Accessed online: www.cdc.gov/lyme/transmission/index.html
  2. Lyme diseases treatment. CDC. 2018. Accessed online: www.cdc.gov/lyme/treatment/index.html
  3. Post-treatment lyme disease syndrome. CDC. 2018. Accessed online: www.cdc.gov/lyme/postlds/index.html
  4. Vaughn MF, Meshnick SR. Pilot study assessing the effectiveness of long-lasting permethrin-impregnated clothing for the prevention of tick bites. Vector Borne Zoonotic Dis. 2011;11(7):869-75.

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