Incidence of methicillin-resistant Staphylococcus aureus infection in a children's hospital in the Washington metropolitan area of the United States, 2003 – 2010

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a major public health threat. In this retrospective cohort study, we included patients with laboratory-confirmed MRSA infections treated at Children's National Medical Center in Washington, District of Columbia between July 2003 and December 2010. The secular trends in the incidence rates of skin/soft tissue and invasive MRSA infections were assessed. Molecular analyses were performed on a subset of patients with invasive infections whose MRSA isolates were available for genotyping. The study identified 3750 patients with MRSA infections. The incidence of MRSA infections peaked in 2007 (incidence rate: 5.34 per 1000 patient-visits) and subsequently declined at a rate of 5% per year. By December 2010, the MRSA incidence rate reached 3.77 per 1000 patient-visits. Seventeen (14.7%) patients with invasive MRSA infections died, and the mortality risk significantly increased if the MRSA infections were healthcare-associated (HA) or if an isolate was resistant to clindamycin and/or trimethoprim/sulfamethoxazole. In conclusion, this study described a descending trend in MRSA infections in children since 2007. Although invasive MRSA infections only accounted for a small portion of the total MRSA infections, they were associated with a high mortality risk. The prevention and control of the spread of MRSA remains a crucial and challenging task.