Borrelioosin

Borrelioosin is a term used for Lyme borreliosis, a tick-borne infectious disease caused by bacteria of the Borrelia burgdorferi sensu lato complex. It is transmitted by Ixodes ticks, most commonly Ixodes ricinus in Europe and Ixodes scapularis (and Ixodes pacificus in North America). The disease can affect multiple organs, most notably the skin, nervous system, heart, and joints.

The clinical presentation typically progresses through stages. Early localized disease often presents with erythema migrans, a slowly expanding red skin lesion at the bite site, sometimes accompanied by fever, malaise, or regional lymph node swelling. Early disseminated disease can involve multiple erythema migrans lesions, cranial neuropathies such as facial palsy, meningitis, radiculopathy, or intermittent migratory joint pains. Late disease is commonly characterized by Lyme arthritis, especially of large joints, and may include chronic neuroborreliosis or mood and cognitive symptoms in a minority of patients.

Diagnosis relies on history of possible tick exposure and characteristic signs, supported by laboratory testing. A two-tier serologic approach is commonly used, with an initial antibody test (ELISA or similar) followed by a confirmatory Western blot. PCR testing can aid in diagnosing infection in synovial fluid or cerebrospinal fluid but is not routinely used for blood samples. Serology may be negative early in the illness.

Treatment typically involves antibiotics. For uncomplicated early disease, doxycycline or amoxicillin for roughly 14–21 days is common; for children, pregnant or breastfeeding women, amoxicillin is often preferred. Severe or neurologic involvement, or persistent arthritis, may require intravenous antibiotics such as ceftriaxone for 14–28 days. Most patients recover with treatment, though a subset may experience persistent symptoms lasting months to years, sometimes referred to as post-treatment Lyme disease syndrome. Prevention focuses on tick avoidance, prompt tick removal, and protective measures in endemic areas.