a1 Division of Paediatric Immunology and Infectious Diseases, UMass Memorial Children's Medical Center, Worcester, MA, USA
a2 Department of Laboratory Medicine, Children's Hospital Boston, Boston, MA, USA
a3 Division of Infectious Diseases, Children's Hospital Boston, Boston, MA, USA
a4 Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO, USA
Community-associated methicillin-resistant S. aureus (CA-MRSA) accounts for a growing proportion of hospital-onset infections, and colonization is a risk factor. This study aimed to determine changes in the prevalence of CA-MRSA colonization in paediatric intensive-care units (ICUs). A total of 495 paediatric patients colonized with MRSA from neonatal, medical, surgical, and cardiac ICUs between 2001 and 2009 were identified. Isolates were characterized by spa type, staphylococcal cassette chromosome (SCC) mec type and the presence of the genes encoding Panton–Valentine leukocidin (PVL). The proportion of patients colonized with MRSA remained stable (average 3·2%). The proportion of isolates with spa type 1, SCCmec type IV and PVL increased over time to maximums in 2009 of 36·1% (P < 0·001), 54·2% (P = 0·03) and 28·9% (P = 0·003), respectively. Antibiotic susceptibility patterns showed increasing proportions susceptible to clindamycin, gentamicin, tetracycline and trimethoprim-sulfamethoxazole (P values <0·001). In conclusion, the proportion of MRSA-colonized children in ICUs with CA-MRSA increased significantly over time.
(Received July 26 2012)
(Revised October 11 2012)
(Accepted October 15 2012)