Impending danger: community-acquired methicillin-resistant Staphylococcus aureus.

In this issue, we are publishing an article which demands immediate attention by the pediatric orthopaedic community, Changing Patterns of Acute Hematogenous Osteomyelitis and Septic Arthritis: Emergence of Community Associated Methicillin Resistant Staphylococcus aureus. This report is a wake-up call to the growing threat of methicillin-resistant Staphylococcus aureus (MRSA) to our patients. Arnold and associates from the Le Bonheur Medical Center (Memphis, Tenn) report a change in the epidemiology and clinical findings of children with musculoskeletal infections. Specifically, they compared patients with methicillin-susceptible Staphylococcus aureus (MSSA) to those with MRSA. They noted that those children with MRSA had more subperiosteal abscesses, more frequent need for a surgical procedure, longer hospital stays, and greater potential for complications such as chronic osteomyelitis. The author’s review of the recent literature finds that the only proposed virulence factor consistently found in these staphylococci is the extracellular toxin Panton-Valentine leukocidin (pvl), encoded by the lukF and the lukS genes. Furthermore, this pvl variation has been associated with necrotizing pneumonia and skin infections in otherwise healthy children and adolescents. Previous reports, both in this journal and others, have found an occasional relationship of MRSA infection and septic emboli. However, in 2005, Gonzalez et al, reported an increasing incidence of community-acquired (CA) MRSA at the Texas Children’s Hospital (Houston, Tex). Their publication reviewed 14 adolescents. Seventy percent of their children had musculoskeletal involvement; 13%, pulmonary involvement; and 4%, vascular complications. There were 3 deaths. In May of this year, the same group reported an additional 9 teenagers who had femoral and popliteal vein thrombosis and osteomyelitis with septic emboli to the lungs. Seven of the children were discovered to have been infected with an organism carrying the Panton-Valentin leukocidin (lukS-PV and lukF-PV) gene using polymerase chain reaction to identify the variants. Recently, we have experienced several patients in Michigan with this exceedingly life-threatening illness. Clearly, there is an increasing prevalence of MRSA associated with musculoskeletal infection in children. This particular genetic variant has been isolated on 3 continents with the United States, France, Switzerland, Australia, and New Zealand reporting cases. More recently, Moran et al in the New England Journal of Medicine noted that the CA MRSA infections have become the most commonly identifiable cause of skin and soft tissue infections among patients presenting to emergency departments in 11 US cities. In their report, 42% percent of these isolates contained pvl genes. Our previous focus has been to identify the organism to select the best antibiotic for treatment. Now, we need to expand our search to identify the genetic variant, so we can be better prepared to deal with the potential complications. All evidence suggests that CA MRSA infection is increasing, primarily in teenagers often in young, healthy boys. It can be virulent in its presentation with vasculitis, thrombophlebitis, and septic emboli to multiple organs. Early recognition and EDITORIAL