Secular Trends in Antibiotic Use Among Neonates 2001-2008

Background: Few data exist on time trends of antibiotic consumption among neonates. Objectives: To assess secular trends in antibiotic consumption in the context of an antibiotic policy and the effect of antibiotic use on the development of antimicrobial resistance and outcome among neonates in a single center. Methods: We performed a prospective cohort study between 2001 and 2008 to monitor antibiotic consumption among neonates. In parallel, we initiated a policy to shorten antibiotic therapy for clinical sepsis and for infections caused by coagulase-negative staphylococci and to discontinue preemptive treatment when blood cultures were negative. Time trend analyses for antibiotic use and mortality were performed. Results: In total, 1096 of 4075 neonates (26.7%) received 1281 courses of antibiotic treatment. Overall, days of therapy were 360 per 1000 patient-days. Days of therapy per 1000 patient-days decreased yearly by 2.8% (P < 0.001). Antibiotic-days to treat infections decreased yearly by 6.5% (P = 0.01) while antibiotic-days for preemptive treatment increased by 3.4% per year (P = 0.03). Mean treatment duration for confirmed infections decreased by 2.9% per year (P < 0.001). No significant upward trend was observed for infection-associated mortality. Of 271 detected healthcare-associated infections, 156 (57.6%) were microbiologically documented. The most frequent pathogens were coagulase-negative staphylococci (48.5%) followed by Escherichia coli (13.5%) and enterococci (9.4%). Rates for extended-spectrum beta-lactamase-producing microorganisms and methicillin-resistant Staphylococcus aureus remained low. Conclusions: Shortening antibiotic therapy and reducing preemptive treatment resulted in a moderate reduction of antibiotic use in the neonatal intensive care unit and did not increase mortality.