[Congenital rubella syndrome after maternal immunization]

A 2.5 year-old girl was found to have congenital rubella syndrome. She presented with microcephaly, mild developmental delay, partial sensorineural deafness and cerebellar atrophy. Blood titers of rubella hemagglutinin were 1/256 and 1/512 (exclusively IgG). She had not had rubella, nor had she been immunized against it. The mother had been immunized against rubella 4 years before her pregnancy with this girl and 2 years later blood hemagglutinin titers were 1/32 and 1/64. She was neither exposed to nor suffered from rubella during the pregnancy. Reinfection with rubella, extremely rare during pregnancy, may occur in women whose hemagglutinin titers are lower than 1/64. Rubella also occurs in women who have been immunized but whose titers, similarly, are lower than 1/64. In some of these women the disease is asymptomatic. In general, reinfection does not result in fetal injury, but cases have been described in which babies of mothers infected in pregnancy were born suffering from various degrees of congenital rubella syndrome.