Late-onset group B streptococcal infection in identical twins: insight to disease pathogenesis.

Late-onset group B streptococcal (GBS) infection affecting identical twins is described. Although exhibiting similar signs and symptoms at presentation, twin A suffered fulminant fatal meningitis while twin B recovered completely. The GBS isolates proved to be genetically identical and possessed equivalent abilities to invade and injure cells of the human blood-brain barrier in vitro. Clinical variables associated with the adverse outcome in twin A were longer duration of fever prior to antibiotics and the development of neutropenia. The case histories and experimental data are reviewed to underscore key features of GBS disease pathogenesis.