The impact of group B streptococcus prophylaxis on late-onset neonatal infections

Objective:to determine trends in late-onset neonatal infections and risk factors for ampicillin/penicillin-resistant microorganisms.study design:data on 584 infants with positive blood, urine or cerebrospinal fluid cultures for bacteria or fungi at 8-30 days of age from 1990 to 2007 were examined and divided into three epochs, based on intrapartum antibiotic prophylactic (iap) practices. pathogens and antibiotic resistance were compared among epochs.result:the number of candidal infections increased over time for the entire population (p=0.006). there was an increased incidence of gram-negative (p=0.009) and candidal infections (p=0.014) among very low-birthweight infants. only escherichia coli infections showed increasing ampicillin resistance over epochs (p=0.006). in regression analysis, ampicillin/penicillin resistance increased with iap use (odds ratio 2.05).conclusion:changing microorganisms and increasing antibiotic resistance in late-onset neonatal infections are likely multifactorial but are increased with iap use, which may identify an at-risk population. increasing candida infections require further investigation.