What is Lyme disease from a tick? - briefly
«Lyme disease» is a bacterial infection caused by the spirochete Borrelia burgdorferi, transmitted to humans through the bite of infected Ixodes ticks. Initial signs often include an expanding erythema migrans rash, followed by fever, fatigue, joint pain, and possible neurologic involvement if untreated.
What is Lyme disease from a tick? - in detail
Lyme disease is a bacterial infection transmitted to humans through the bite of infected Ixodes ticks. The responsible pathogen, Borrelia burgdorferi sensu lato, resides in the tick’s midgut and migrates to the salivary glands during feeding, allowing direct inoculation into the host’s skin.
The infection progresses through distinct clinical stages. Early localized disease appears within days to weeks after exposure and is characterized by a circular erythema migrans lesion, often expanding to a diameter of 5‑15 cm. Accompanying symptoms may include fever, chills, fatigue, headache, and muscle aches. If untreated, the infection can advance to early disseminated disease, presenting with multiple erythema migrans lesions, facial nerve palsy, meningitis, and carditis. Late-stage manifestations develop months to years later and may involve arthritis, particularly of large joints, and neurologic complications such as peripheral neuropathy or encephalopathy.
Diagnosis relies on a combination of clinical assessment and laboratory testing. Recommended serologic algorithms consist of:
- An initial enzyme‑linked immunosorbent assay (ELISA) to detect IgM and IgG antibodies.
- Confirmation with a Western blot assay, interpreting specific protein bands according to established criteria.
In cases where serology is inconclusive but clinical suspicion remains high, polymerase chain reaction (PCR) testing of synovial fluid or cerebrospinal fluid may be employed.
Treatment protocols depend on disease stage and patient characteristics. First‑line therapy for uncomplicated early infection includes doxycycline administered orally for 10‑21 days. Alternative regimens, such as amoxicillin or cefuroxime axetil, are indicated for children, pregnant women, or individuals with doxycycline intolerance. More severe manifestations, such as Lyme carditis or meningitis, require intravenous ceftriaxone for 14‑28 days.
Prevention focuses on minimizing tick exposure and prompt removal of attached ticks. Effective measures comprise:
- Wearing long sleeves and pants in endemic areas.
- Applying EPA‑registered repellents containing DEET, picaridin, or IR3535 to skin and clothing.
- Conducting thorough body checks after outdoor activities and removing ticks with fine‑tipped tweezers, grasping the head as close to the skin as possible, and pulling steadily without twisting.
Understanding the pathogen’s life cycle, clinical progression, diagnostic criteria, and therapeutic options enables timely intervention and reduces the risk of long‑term complications associated with tick‑borne Lyme disease.