Community-associated Methicillin-Resistant Staphylococcus aureus Strains in Pediatric Intensive Care Unit

EID Journal Home > Volume 16, Number 4–April 2010

Volume 16, Number 4–April 2010
CME ACTIVITY
Community-associated Methicillin-Resistant Staphylococcus aureus Strains in Pediatric Intensive Care Unit
Medscape, LLC is pleased to provide online continuing medical education (CME) for this journal article, allowing clinicians the opportunity to earn CME credit. This activity has been planned and implemented in accordance with the Essential Areas and policies of the Accreditation Council for Continuing Medical Education through the joint sponsorship of Medscape, LLC and Emerging Infectious Diseases. Medscape, LLC is accredited by the ACCME to provide continuing medical education for physicians. Medscape, LLC designates this educational activity for a maximum of 0.5 AMA PRA Category 1 Credits™. Physicians should only claim credit commensurate with the extent of their participation in the activity. All other clinicians completing this activity will be issued a certificate of participation. To participate in this journal CME activity: (1) review the learning objectives and author disclosures; (2) study the education content; (3) take the post-test and/or complete the evaluation at www.medscapecme.com/journal/eid; (4) view/print certificate.

Learning Objectives
Upon completion of this activity, participants will be able to:

Identify risk factors among children for being a community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) carrier.
Recognize the benefits of screening for MRSA colonization in children being admitted to the hospital.
Predict a consequence of undetected CA-MRSA carriers admitted to a hospital setting.
CME Editor
Carol Snarey, Copyeditor, Emerging Infectious Diseases. Disclosure: Carol Snarey has disclosed no relevant financial relationships.

CME Author
Charles P. Vega, MD, Associate Professor; Residency Director, Department of Family Medicine, University of California, Irvine, CA, USA. Disclosure: Charles P. Vega, MD, has disclosed no relevant financial relationships.

Authors
Disclosures: Aaron M. Milstone, MD, MHS, has disclosed the following relevant financial relationship: received grants for clinical research from Sage Products, Inc. Karen C. Carroll, MD, has disclosed the following relevant relationships: served as an advisor or consultant for Quidel Diagnostics; OpGen, Inc.; Boehringer Ingelheim Pharmaceuticals, Inc.; received grants for clinical research from BD GeneOhm; Ibis Biosciences, Inc.; MicroPhage, Inc. Tracy Ross, BS, and K. Alexander Shangraw, MSPH, have disclosed no relevant financial relationships. Trish M. Perl, MD, MSc, has disclosed the following relevant financial relationships: served as an advisor or consultant for Cadence Pharmaceuticals; 3M; TheraDoc Inc.; received grants for clinical research from US Centers for Disease Control and Prevention; Merck & Co., Inc.; Sage Products, Inc.; US Department of Veterans Affairs.


EID Journal Home > Volume 16, Number 4–April 2010

Volume 16, Number 4–April 2010
Research
Community-associated Methicillin-Resistant Staphylococcus aureus Strains in Pediatric Intensive Care Unit1
Aaron M. Milstone, Karen C. Carroll, Tracy Ross, K. Alexander Shangraw, and Trish M. Perl
Author affiliation: The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA

Suggested citation for this article

Abstract
Virulent community-associated methicillin-resistant Staphylococcus-aureus (CA-MRSA) strains have spread rapidly in the United States. To characterize the degree to which CA-MRSA strains are imported into and transmitted in pediatric intensive care units (PICU), we performed a retrospective study of children admitted to The Johns Hopkins Hospital PICU, March 1, 2007–May 31, 2008. We found that 72 (6%) of 1,674 PICU patients were colonized with MRSA. MRSA-colonized patients were more likely to be younger (median age 3 years vs. 5 years; p = 0.02) and African American (p<0.001) and to have been hospitalized within 12 months (p<0.001) than were noncolonized patients. MRSA isolates from 66 (92%) colonized patients were fingerprinted; 40 (61%) were genotypically CA-MRSA strains. CA-MRSA strains were isolated from 50% of patients who became colonized with MRSA and caused the only hospital-acquired MRSA catheter-associated bloodstream infection in the cohort. Epidemic CA-MRSA strains are becoming endemic to PICUs, can be transmitted to hospitalized children, and can cause invasive hospital-acquired infections. Further appraisal of MRSA control is needed.

Methicillin-resistant Staphylococcus aureus (MRSA) frequently infects children. Traditionally, MRSA infections were confined to those who frequented healthcare facilities or had predisposing healthcare-associated risk factors. In the 1990s, reports emerged of MRSA infections in healthy children in the community who had no predisposing risk factors (1). Community-onset MRSA infections were caused by MRSA strains belonging to the genotypes USA300 and USA400 (identified by pulsed-field gel electrophoresis [PFGE]), also referred to as the community-associated MRSA (CA-MRSA) strains (2,3). These CA-MRSA strains are associated with increased production of toxins and are less resistant to antimicrobial drugs than are traditional hospital-acquired MRSA (HA-MRSA) strains (4,5). Although CA-MRSA strains usually cause mild skin and soft tissue infections, they can also cause severe and fatal disease (6–8).

As the community prevalence of MRSA has risen (9), more children colonized or infected with MRSA have been admitted to hospitals (10–12), especially with phenotypic CA-MRSA strains. Notably, CA-MRSA strains can cause outbreaks in hospitals (13) and have become a frequent cause of hospital-onset infections (14,15). Aside from ways to manage outbreaks (16) and a report that clinical cultures underestimate MRSA prevalence (17), little is known about the prevalence of MRSA colonization of hospitalized children. The degree to which CA-MRSA strains are imported into and transmitted in high-risk settings such as pediatric intensive care units (PICUs) has not been determined. Understanding the effects of MRSA in hospitalized children is essential to guide, assess, and plan MRSA prevention and control programs among hospitalized children. Our objectives were to measure the prevalence of MRSA colonization at the time of admission to the PICU and to determine the effects of CA-MRSA strains on MRSA colonization, transmission, and hospital-acquired infections in the PICU.


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Suggested Citation for this Article
Milstone AM, Carroll KC, Ross T, Shangraw A, Perl TM. Community-associated methicillin-resistant Staphylococcus aureus strains in pediatric intensive care unit. Emerg Infect Dis [serial on the Internet]. 2010 Apr [date cited]. Available from http://www.cdc.gov/EID/content/16/4/647.htm

DOI: 10.3201/eid1604.090107