Continuous surveillance to reduce extended-spectrum β-lactamase Klebsiella pneumoniae colonization in the neonatal intensive care unit

Abstract

Background: Clinical illness caused by resistant bacteria usually represents a wider problem of asymptomatic colonization. Active surveillance with appropriate institution of isolation precautions represents a potential mechanism to control colonization and reduce infection. The neonatal intensive care unit (NICU) is an environment particularly appropriate for such interventions. Neonates are rarely colonized by resistant bacteria on admission and staff enthusiasm for infection control is high.

Objective: To reduce extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL-KP) acquisition amongst neonates through a continuous active surveillance intervention.

Methods: Fecal ESBL-KP cultures were performed weekly on all neonates over 4 years. Neonates with positive cultures were managed with contact precautions by dedicated nurses separately from other neonates. ESBL-KP acquisition amongst neonates staying >7 days was compared for the consecutive years. A subset of ESBL-KP isolates was typed with pulsed-field gel electrophoresis (PFGE).

Results: Surveillance cultures were obtained from 1,482/1,763 (84%) neonates over 4 years. ESBL-KP acquisition decreased continuously from 94/397 (24%) neonates in 2006 to 33/304 (11%) in 2009 (p < 0.001, hazard ratio 0.75, 95% confidence interval 0.66-0.85, p < 0.001 for comparison of years). Hospital-wide ESBL-KP acquisition did not decrease outside the NICU. PFGE identified identical ESBL-KP strains from multiple neonates on six occasions and different strains from single neonates on seven occasions.

Conclusions: ESBL-KP is probably both imported into and spread within the NICU. Continuous long-term surveillance with cohorting was associated with a decrease in ESBL-KP acquisition within the NICU. This low-risk intervention should be considered as a means to decrease neonatal acquisition of resistant bacteria.