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Biology for the Global Citizen

A Closer Look at Lyme Disease

by George Shiflet
Copyright © 2024 George Shiflet. All rights reserved.

See “Ticks: Well-Adapted Parasites” for information on various structural and physiological adaptations that make ticks successful parasites.

See “Magic Pill? Preventing Tick-Borne Diseases in Human Beings” for a discussion of recent research on a vaccine and a drug against ticks.

 

In the U.S, Lyme disease is the most commonly reported disease that is spread through bites of ticks. If untreated, the bacterium that causes the disease, Borrelia burgdorferi, can produce rashes, fever, headaches, musculoskeletal pain, fatigue, and irregular heartbeat. In many cases, a characteristic rash (bull’s-eye) forms (Figure 1). If undiagnosed and untreated, the bacterium may cause severe joint pain and swelling, neurological symptoms (e.g., neck stiffness, encephalitis, neuropathy, facial palsy), irregular heartbeat, etc.

 

Figure 1.  Leaf of a stinging plant.

Figure 1. Erythema migrans (bull’s-eye rash) which forms in most, but not all cases of Lyme disease within an average of 7 days from infection.

Source: Centers for Disease Control and Prevention (NIH), https://commons.wikimedia.org/wiki/File:Erythema_migrans.jpg

 

Many people are often unaware of a tick bite, and not every tick bears the disease agent. For the tick, there is some delay in finding the proper attachment site. Furthermore, it is thought that more than 24 hours are required for a tick to pass on the Borrelia burgdorferi to its host. Obviously, you can help to prevent the disease by avoiding habitats for ticks, wearing protective and treated clothing, and checking yourself for ticks immediately after being in possible tick habitats.

to its host. Obviously, you can help to prevent the disease by avoiding habitats for ticks, wearing protective and treated clothing, and checking yourself for ticks immediately after being in possible tick habitats Borrelia that tests can detect. So, often false negatives are seen early in the infection. Also, the tests are never 100% accurate. In fact, certain viruses and other bacteria sometime bear similar proteins to the Lyme bacterium, resulting in cross-reactions with the Lyme tests. Still, it is better to get tested to help your physician chart your best treatment.

Treatment for diagnosed acute Lyme Disease is 10-14 days of antibiotics (doxycycline, amoxicillin, or cefuroxime axetil). In most cases, this treatment will lead to rapid and complete recovery. However, in ~10% of the cases, patients seem to develop PTLDS, post-treatment Lyme disease syndrome, sometimes referred to as chronic Lyme disease. With the recognition of long COVID, PTLDS is getting more attention. For years, PTLDS patients suffer from various devastating symptoms, such as various neurological conditions, heart palpitations, arthritis, and chronic pain, sometimes with a misdiagnose of Multiple Sclerosis. Researchers are searching for the factors (e.g., genetic factors, microbiomes, medical histories) that make some people susceptible to PTLDS and working to improve the testing/diagnostic procedures that recognize the disease when it occurs.

 

References

CDC. “Testing Protocol.” 2024. https://www.cdc.gov/lyme/media/pdfs/2024/05/Suggested-Reporting-Language-Interpretation-and-Guidance-Regarding-Lyme-Disease-Serologic-Test-Results.pdf.

Columbia University Medical Center. “Testing Information.” 2024. https://www.columbia-lyme.org/diagnosis#:~:text=Unfortunately%20culturing%20Lyme%20disease%20is,the%20blood%20or%20spinal%20fluid.