MRSA Research Today is a free monthly online journal that collates and summarizes the latest research about MRSA, including details on methicillin-resistant staphylococcus aureus, hospitals, infection, antibiotic resistance, superbugs.

Infective pyomyositis and myositis in children in the era of community-acquired, methicillin-resistant Staphylococcus aureus infection.

Pannaraj PS, Hulten KG, Gonzalez BE, Mason EO, Kaplan SL

Section of Infectious Diseases, Department of Pediatrics, Baylor College of Medicine and Texas Children's Hospital, Houston, TX 77030, USA. pannaraj@bcm.tmc.edu

BACKGROUND: Cases of pyomyositis and myositis have been increasing in frequency at Texas Children's Hospital (Houston) since 2000. The increase appears to correlate with the emergence of community-acquired methicillin-resistant Staphylococcus aureus (MRSA). METHODS: The medical records of patients with pyomyositis and myositis hospitalized at Texas Children's Hospital during the period from January 2000 through December 2005 were reviewed. Available S. aureus isolates were obtained for susceptibility testing, to determine the presence of pvl (lukS-PV and lukF-PV), and for pulsed-field gel electrophoresis analysis. RESULTS: Forty-five previously healthy children with bacterial pyomyositis or myositis were analyzed. The causes were S. aureus (in 57.8% of children) and Streptococcus pyogenes (in 2.2%); 40.0% of children had negative culture results. The number of cases increased between 2000 and 2005, primarily as a result of an increase in the prevalence of community-acquired MRSA. The mean patient age was 5.5 years (range, 0.06-15 years). The thigh (40.0% of children) and pelvis (28.9%) were the most commonly affected sites. The mean abscess diameter was 3.5 cm. Eighteen children required at least 1 muscle drainage procedure. Of the 24 available S. aureus isolates (15 community-acquired MRSA isolates and 9 community-acquired, methicillin-susceptible S. aureus [MSSA] isolates), 16 were found to be USA300 by pulsed-field gel electrophoresis, and 17 carried pvl. Patients with community-acquired MRSA, USA300, and/or pvl-positive strains required more drainage procedures than did those with community-acquired MSSA, non-USA300, and/or pvl-negative strains (81% vs. 40% [P=.05], 82% vs. 29% [P=.02], and 81% vs. 38% [P=.07], respectively). CONCLUSIONS: Community-acquired MRSA is an increasing cause of pyomyositis and myositis in children. Community-acquired MRSA, USA300, pvl-positive S. aureus isolates caused more severe disease than did community-acquired MSSA, non-USA300, and pvl-negative isolates, respectively.

Published 19 September 2006 in Clin Infect Dis, 43(8): 953-60.
Full-text of this article is available online (may require subscription).

© 2004-2008 MRSA Research Today. All Rights Reserved.