Outbreak of skin and soft tissue infections in a hospital newborn nursery in Italy due to community-acquired meticillin-resistant Staphylococcus aureus USA300 clone

Abstract

Community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA) is responsible for severe infections in previously healthy people acquired in the community in different areas of the world. To report an outbreak of CA-MRSA in a hospital newborn nursery in northern Italy in September-October 2010, its investigation and control measures. The epidemiology of the outbreak is reported. The investigation included screening neonates, parents and staff for MRSA carriage. Molecular strain typing was performed on MRSA isolates. The outbreak affected nine neonates with three severe infections. In addition, four mothers had postpartum mastitis, and three mothers and one father had skin infection. The outbreak strain belonged to the USA300 CA-MRSA clone. Asymptomatic carriage of the outbreak strain was found among neonates, parents and hospital staff. The implementation of appropriate infection control measures in the hospital terminated the outbreak. To our knowledge, this is the first report of a hospital outbreak caused by the USA300 CA-MRSA clone in Europe. It is important to reinforce infection control measures, particularly in high-risk groups, such as neonates, to prevent USA300 from becoming endemic in European hospitals.