Methicillin-Resistant Staphylococcus aureus Colonization: A Three-Year Prospective Study in a Neonatal Intensive Care Unit in Italy

Abstract

An MRSA strain belonging to the tst1 positive, UK-EMRSA-15/ "Middle Eastern Variant" appeared to be endemic in the NICU under investigation. During the three-year period, substantial changes occurred in case-mix of patients moving towards a higher susceptibility to MRSA colonization. The infection control procedures were able to decrease the colonization rate from more than 40% to approximately 10%, except for an outbreak due to a CA-MRSA strain, ST1-MRSA-IVa, and a transient increase in the colonization prevalence rate coincident with a period of substantial overcrowding of the ward. Active surveillance and molecular typing contributed to obtain a reliable picture of the MRSA dissemination in NICU.