Epidemiologic Investigation of an Outbreak of Vancomycin-resistant Enterococcus in a Tertiary Care Neonatal Intensive Care Unit

Abstract

<h3>Background</h3> Increasingly prevalent vancomycin-resistant Enterococcus (VRE) amongst neonatal and pediatric patients may cause outbreaks and result in infections associated with significant morbidity. We describe a VRE outbreak in our 52-bed neonatal intensive care unit (NICU), its control methods, and recommendations for prevention. <h3>Methods</h3> This outbreak was declared on August 7, 2018, upon discovery of two new cases one week after the index case identification in our NICU. Outbreak management strategies implemented included contact precautions, weekly unit VRE screening, optimization of hand hygiene, enhanced environmental cleaning and disinfection, cohorting of cases and healthcare worker (HCW) and parent education. Typing by pulsed-field gel electrophoresis (PFGE) was performed for all outbreak strains and compared to VRE strains from the adjoining adult hospital. <h3>Results</h3> Six VRE cases occurred during the 4-week-long outbreak: 5 were colonizations and 1 patient eventually developed a central line-associated bloodstream infection. All colonized neonates had been physically located in the same area of the NICU at some point prior to becoming colonized. Hand hygiene compliance was 62% at the start of the outbreak. PFGE typing confirmed horizontal transmission of a single strain (pulsovar E) which was not related to other typed strains from the adult hospital. The source of the outbreak was not identified. None of the mothers of the colonized patients had been screened for VRE antenatally. In total, 348 VRE screening tests were performed. After three consecutive weeks without new cases, the outbreak was declared over. The need for HCW and parent education on VRE prevention and control was identified. <h3>Conclusions</h3> A multi-faceted approach to controlling a VRE outbreak is key, with emphasis on hand hygiene and HCW and parent education, especially as VRE prevalence in pediatric centers is low. In addition, antenatal maternal screening for VRE could be beneficial to identify neonates at risk for colonization.