No increase in rates of early-onset neonatal sepsis by antibiotic-resistant group B Streptococcus in the era of intrapartum antibiotic prophylaxis

Objective The aim of this study was to assess the rate of early-onset neonatal sepsis by antibiotic-resistant group B Streptococcus. Study design The time-trend study was conducted at a tertiary care center over the following periods: no protocol for group B Streptococcus prophylaxis (1990 to 1992), risk-based protocol (1993 to 1996), and screening-based protocol (1997 to 2002). Results A total of 120,952 neonates were born with 118 cases of group B Streptococcus early-onset neonatal sepsis. The rate of group B Streptococcus early-onset neonatal sepsis decreased significantly (from 2.0 to 1.1 to 0.4 per 1000 births, P< .0001). No group B Streptococcus isolate was resistant to ampicillin, penicillin, cefazolin, or vancomycin. From 1997 to 2002, there were 3 clindamycin-resistant group B Streptococcus isolates (14%). The rate of erythromycin-resistant group B Streptococcus early-onset neonatal sepsis did not change (from 0.14 to 0.03 to 0.08 per 1000 births, P = .6). However, cases of erythromycin-resistant group B Streptococcus early-onset neonatal sepsis accounted for an increasing proportion of the remaining cases of group B Streptococcus early-onset neonatal sepsis (from 7.0% to 2.6% to 23.8%, P = .07). Conclusion We found no increase in rates of antibiotic-resistant group B Streptococcus early-onset neonatal sepsis.