Recurrent group B streptococcal infections in infants: Clinical and microbiologic aspects

Objective: To describe the potential for recurrence of group B streptococcal (GBS) infection in infants, using pulsed-field gel electrophoresis as an epidemiologic tool. Design: Retrospective review of cases identified by laboratory records and review of the literature. Setting: Neonatal nurseries of a county hospital system. Methods: Retrospective review of infants with second episodes of GBS bacteremia or meningitis. Digestion of chromosomal DNA with the restriction enzyme Sma I and separation of fragments by use of contour-clamped homogeneous electric field. Results: Nine cases of recurrent GBS infection were identified during a 14-year period. Eight of the nine infants were born at 25 to 36 weeks of gestation, and one was born at term. The first episode of invasive GBS infection occurred at a mean age of 10.4 days (median, 3 days; range, 1 to 27 days). Parenteral antibiotic therapy was administered for a mean of 13.9 days (median, 14 days; range, 10 to 21 days). Recurrence occurred at a mean age of 42.3 days (median, 48 days; range, 23 to 68 days). One patient died during the second episode; eight infants survived to discharge home. Of seven sets of isolates analyzed from first and second GBS episodes, five were confirmed to be the same genotypically. Conclusion: Recurrence of GBS disease in infants may be associated with the original infecting strain or a second acquired strain. (J PEDIATR 1994;125:931-8).