Group B Streptococcus

1. Group B Streptococcus Streptococcus agalactiae

2. GBS Epidemiology • Colonizes the genital tract; risk groups include: • Infants: Colonization during delivery may results in invasive disease • Pregnant and post-partum women • Non-pregnant adults • Elderly • Individuals with chronic underlying disease

3. Burden of Invasive GBS Disease, 1989-1990, AtlantaNEJM, 1993; 328:1807

4. Age Distribution of GBS in Infants and NeonatesClin Microbiol Rev, 1998; 11:497.

5. Incidence of Invasive GBS Disease with Age, 1989-1990, AtlantaNEJM, 1993; 328:1807

6. Risk Factors for Early Onset Group B Streptococcal DiseaseBMJ, 2002; 325:308

7. Prenatal GBS screening at 35-37 weeks: Offer penicillin intrapartum if: GBS (+) Culture not done and risk factors present Previous infant had IGBS disease Mother had GBS bacteriuria, this pregnancy Delivery occurred at < 37 weeks gestation Risk factor screening: Offer penicillin intrapartum if: Previous infant had IGBS disease Mother had GBS bacteriuria, this pregnancy Delivery occurred at < 37 weeks gestation Duration of ruptured membranes > 18 hours Intrapartum temperature > 100.4F 1996 Recommendations (CDC)MMWR, 1996; 45(No. RR-7)

8. Reduction in IGBS Disease Emerg Infect Dis, 2001; 7:92

9. Population-based Comparison of Strategies to Prevent Early-Onset GBSNEJM, 2002; 347:233

10. 2002 Recommendations (CDC)MMWR, 2002; 51(No. RR-11) • Universal screening of all women at 35-37 weeks gestation • Prophylax: • Previous infant with IGBS • GBS bacteriuria this pregnancy • Positive GBS screen this pregnancy unless • C-section planned in the absence of labor or rupture of membranes • Unknown GBS status AND delivery at < 37 weeks, rupture of membranes > 18 hours, or intrapartum temperature > 100.4 F

11. VaccineArch Dis Child, 2003; 88:375-8 • Phase I trial completed • Women at 32-34 weeks • Serum antibody and cord blood antibody • Elevated after immunization • Promoted killing of GBS in vitro • May protect against both late and early onset disease • Barriers • Pharmaceutical leadership / liability issues

12. GBS Clinical Presentation • Neonates • Sepsis, meningitis, pneumonia, cellulitis, osteomyelitis, septic arthritis • Pregnant and post-partum women • Mild UTI, sepsis; less commonly osteomyelitis, endocarditis, meningitis • Non-pregnant adults • Bacteremia, skin or soft tissue infections > pneumonia > urosepsis > endocarditis > peritonitis > meningitis > empyema

13. IGBS Case Definition (draft) • Clinical description • Invasive group B streptococcal infections may manifest as any of several clinical syndromes, including pneumonia, deep soft-tissue infection, meningitis, peritonitis, osteomyelitis, septic arthritis, postpartum sepsis (i.e., puerperal fever), neonatal sepsis, and nonfocal bacteremia.

14. IGBS Case Definition (draft) • Laboratory criteria for diagnosis • Isolation of group B Streptococcus (Streptococcus agalactiae) by culture from a normally sterile site (e.g., blood or cerebrospinal fluid, or, less commonly, joint, pleural, or pericardial fluid) • Case classification • Confirmed: a case that is laboratory confirmed

15. Public Health Action • Case ascertainment • Case investigation: • Fill out yellow card and CDC meningitis form • Follow up early onset disease (onset < 7 days of age) to determine if mother was cultured/prophylaxed.

16. GBS - Summary • Important pathogen of: • Newborns • Pregnant and post-partum women • Non-pregnant adults with underlying disease • Vaccine in development • Investigation • Demographics, site of infection, source of isolate (establish baseline incidence before vaccine licensure) • Follow-up of early-onset disease