Borrelioosit

Borrelioosit, also known as Lyme borreliosis, is a bacterial infection caused by the Borrelia burgdorferi sensu lato complex. It is transmitted to humans through bites of Ixodes ticks, notably Ixodes ricinus in Europe and Ixodes scapularis in North America, with reservoir hosts including small mammals and birds. The disease encompasses several Borrelia species and can present differently depending on geographic region.

Transmission typically requires extended tick attachment, often more than 24 hours. The illness usually progresses through stages: early localized disease most commonly presents with erythema migrans, a expanding circular skin rash that may be accompanied by flu-like symptoms. Early disseminated disease can involve multiple rashes, facial nerve palsy, or meningitis, while late manifestations may include mosit, intermittent arthritis, particularly in large joints, and chronic neuroborreliosis. A chronic skin manifestation called acrodermatitis chronica atrophicans occurs in some European strains. Not all patients experience every stage, and symptoms may overlap.

Diagnosis relies on clinical assessment, especially when erythema migrans is present, but serological testing supports confirmation. Two-tier testing (an initial antibody screen followed by a confirmatory test) is commonly used; antibodies may be absent early in infection. Polymerase chain reaction testing can aid in certain contexts, such as joint fluid analysis. Treatment with antibiotics is generally effective, with doxycycline, amoxicillin, or cefuroxime axetil used for uncomplicated cases; more serious neurological or late disease often requires intravenous antibiotics such as ceftriaxone.

Prevention focuses on tick avoidance and prompt removal, protective clothing, repellents, and tick checks after outdoor exposure. There is currently no widely available human Lyme vaccine. Most treated patients recover, though a subset may experience persistent symptoms after therapy.