Meningitis due to Borrelia burgdorferi in the initial stage of Lyme disease.

Borrelia burgdorferi (B.b.) was isolated from cerebrospinal fluid from two children with aseptic meningitis. Serology for B.b. was initially negative or borderline and became positive during the subsequent course. Children with aseptic meningitis of unknown origin should be re-evaluated within 1 month to detect possible increasing antibody titres to B.b. Aseptic meningitis may be a stage 1 manifestation of Lyme disease.