title: Etiology of septic arthritis in children: an update for the new millennium.
abstract: OBJECTIVE
  We sought to describe the causative organisms and joints involved in cases of pediatric septic arthritis in the post-Haemophilus influenzae type B and post-pneumococcal vaccine age and in the age of increasing infection with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA).
  
  
  METHODS
  This was a retrospective chart review of all children younger than 13 years presenting to our tertiary care pediatric emergency department between January 1, 2003, and December 31, 2007, with the diagnosis of septic arthritis. We reviewed the results of synovial fluid Gram stain and synovial fluid and blood culture. We defined septic arthritis as any of these 3 tests being positive for a known pathogen. We report patient characteristics, joint(s) involved, and organisms identified in these cases.
  
  
  RESULTS
  We describe 13 cases of septic arthritis. Fifteen joints were involved. The most common joint involved was the hip (6/15) followed by the elbow (3/15), knee (2/15), and ankle (2/15). The most common organism involved was methicillin-sensitive S aureus (6/13), followed by CA-MRSA (2/13) and Streptococcus pneumoniae (2/13).
  
  
  CONCLUSIONS
  Our results support continued concern for involvement of the hip and knee in cases of pediatric septic arthritis and consideration of other joints such as the elbow. Our data also suggest that empiric antibiotic coverage for CA-MRSA is indicated in cases of pediatric septic arthritis, as well as continued coverage for methicillin-sensitive S aureus and S pneumoniae.
authors.affiliation: Division of Pediatric Emergency Medicine, Department of Emergency Medicine, Loma Linda University Children's Hospital, Loma Linda, CA 92354, USA. tpyoung@llu.edu
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Young
authors.forename: Lee
authors.initials: L
authors.lastname: Maas
authors.forename: Andrea W
authors.initials: AW
authors.lastname: Thorp
authors.forename: Lance
authors.initials: L
authors.lastname: Brown
mesh_terms: D000046:Academic Medical Centers / Q000706:statistics & numerical data; D001170:Arthritis, Infectious / Q000209:etiology* / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus; D011008:Pneumococcal Infections / Q000150:complications; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000150:complications / Q000382:microbiology; D013296:Streptococcus pneumoniae