Community-acquired methicillin-resistant Staphylococcus aureus in children with no identified predisposing risk.

CONTEXT Community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infections in children have occurred primarily in individuals with recognized predisposing risks. Community-acquired MRSA infections in the absence of identified risk factors have been reported infrequently. OBJECTIVES To determine whether community-acquired MRSA infections in children with no identified predisposing risks are increasing and to define the spectrum of disease associated with MRSA isolation. DESIGN Retrospective review of medical records. PATIENTS Hospitalized children with S aureus isolated between August 1988 and July 1990 (1988-1990) and between August 1993 and July 1995 (1993-1995). SETTING The University of Chicago Children's Hospital. MAIN OUTCOME MEASURES Prevalence of community-acquired MRSA over time, infecting vs colonizing isolates, and risk factors for disease. RESULTS The number of children hospitalized with community-acquired MRSA disease increased from 8 in 1988-1990 to 35 in 1993-1995. Moreover, the prevalence of community-acquired MRSA without identified risk increased from 10 per 100000 admissions in 1988-1990 to 259 per 100000 admissions in 1993-1995 (P<.001), and a greater proportion of isolates produced clinical infection. The clinical syndromes associated with MRSA in children without identified risk were similar to those associated with community-acquired methicillin-susceptible S aureus. Notably, 7 (70%) of 10 community-acquired MRSA isolates obtained from children with an identified risk were nonsusceptible to at least 2 drugs, compared with only 6 (24%) of 25 isolates obtained from children without an identified risk (P=.02). CONCLUSIONS These findings demonstrate that the prevalence of community-acquired MRSA among children without identified risk factors is increasing.