We identified 90 patients with tick-borne erythema migrans in the Union of Soviet Socialist Republics (USSR) in areas from the western Baltic Republics to the Maritime Territory on the Pacific Ocean. Symptoms associated with the erythema included fever, malaise and fatigue, headache, myalgias, arthralgias, or regional lymphadenopathy. Within two weeks to four months, 58 (64%) of the patients developed neurological abnormalities, particularly radicular pain, cranial neuritis, or lymphocytic meningitis, and four (4%) patients developed monoarticular or oligoarticular arthritis. We tested the sera from 35 Soviet patients by using an isolate from the United States. The serological data showed elevated IgM and/or IgG antibody titers to Borrelia burgdorferi in 2 of 10 patients with erythema migrans, 15 of 21 with neurological abnormalities, and 2 of 4 with arthritis. Our observations suggest that
Lyme borreliosis occurs in diverse areas of the USSR.