title: Changing trends in acute osteomyelitis in children: impact of methicillin-resistant Staphylococcus aureus infections.
abstract: BACKGROUND
  Staphylococcus aureus remains the most common etiologic agent of acute osteomyelitis in children. Recently, methicillin-resistant S. aureus (MRSA) has emerged as a major pathogen.
  
  
  METHODS
  Records of all children admitted with acute osteomyelitis from January 1999 to December 2003 were reviewed. For the comparative analysis, the study population was evenly distributed in 2 periods: period A, January 1999 to June 2001; n = 113; and period B, July 2001 to December 2003; n = 177. In addition, clinical findings of MRSA osteomyelitis were compared with non-MRSA osteomyelitis, including methicillin-sensitive S. aureus infections.
  
  
  RESULTS
  Two hundred ninety children (60% male subjects) with acute osteomyelitis were identified. Median (25th-75th percentile) age at diagnosis was 6 years (range, 2-11 years). Significant clinical findings included the following: localized pain (84%), fever (67%), and swelling (62%). Affected bones included the following: foot (23%), femur (20%), tibia (16%), and pelvis (7%). Thirty-seven percent of blood cultures were positive, and a bacterial isolate was obtained in 55% of cases. Bacteria most frequently isolated included the following: methicillin-sensitive S. aureus (45%) (57% in period Avs 40% in period B), MRSA (23%) (6% in A vs 31% in B; P < 0.001), Streptococcus pyogenes (6%), and Pseudomonas aeruginosa (5%). Children with MRSA compared with those with non-MRSA osteomyelitis had significantly greater erythrocyte sedimentation rate and C-reactive protein values on admission and increased length of hospital stay, antibiotic therapy, and overall rate of complications. We observed significant changes in antibiotic therapy related to increased use of agents with activity against MRSA.
  
  
  CONCLUSIONS
  Methicillin-resistant S. aureus was isolated more frequently in the second study period and was associated with worse clinical outcomes.
authors.affiliation: Department of Pediatrics, Division of Pediatric Infectious Diseases, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
authors.forename: Jesús
authors.initials: J
authors.lastname: Saavedra-Lozano
authors.forename: Asunción
authors.initials: A
authors.lastname: Mejías
authors.forename: Naveed
authors.initials: N
authors.lastname: Ahmad
authors.forename: Estrella
authors.initials: E
authors.lastname: Peromingo
authors.forename: Monica I
authors.initials: MI
authors.lastname: Ardura
authors.forename: Sara
authors.initials: S
authors.lastname: Guillen
authors.forename: Ali
authors.initials: A
authors.lastname: Syed
authors.forename: Dominick
authors.initials: D
authors.lastname: Cavuoti
authors.forename: Octavio
authors.initials: O
authors.lastname: Ramilo
mesh_terms: D000208:Acute Disease; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D016015:Logistic Models; D008297:Male; D016106:Methicillin Resistance; D010019:Osteomyelitis / Q000453:epidemiology* / Q000382:microbiology*; D015995:Prevalence; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000453:epidemiology*; D013211:Staphylococcus aureus; D013781:Texas / Q000453:epidemiology