Persistent rubella-specific IgM-antibody in the cerebrospinal fluid of a child with congenital rubella.

Rubella-specific IgM-antibody was detected, using a solid-phase radioimmunoassay (RIA) method, in the CSF of a child with congenital rubella at ages 3 and 4 years. No rubella-specific Igm was found in the CSF of 20 other children with congenital rubella, and the ratios of rubella-specific IgG RIA antibody titres in serum and CSF were normal.