Background The frequency of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is increasing among youth in AR, as evidenced by an increase in the frequency of MRSA among outpatient culture isolates of S. aureus (12% in 2002; 48% in 2004).
Purpose To investigate microbial etiologies, treatment, and outcome of pediatric patients treated for septic arthritis during the recent era of increased CA-MRSA.
Methods Retrospective reviews of medical records identified patients treated for septic arthritis in 2004; demographic and clinical data were gathered and reviewed.
Results 68 patients have been identified; 50 chart reviews have been completed. Microbial cultures were positive in 3 of 15 patients (20%) with synovial fluid cell counts < 75,000/mL vs. 13 of 26 patients (50%) with counts > 75,000/mL. Joint isolates included 7 methicillin-sensitive S. aureus, 5 group A streptococci, 2 K. kingae, 1 Actinomyces, and 1 E. coli. MRSA was isolated from the blood of two patients diagnosed with sacroiliac joint infection by MRI; neither had a joint aspirate performed. All patients had indwelling catheters placed for administration of parenteral antibiotics; 11 of 50 (22%) had catheter-related complications, which included 6 cases of premature line removal, 2 cases of fever and bacteremia, and 1 case of E. coli sepsis. Only 1 of 41 patients (2%) evaluated long-term exhibited residual joint dysfunction.
Conclusion MRSA appears rare as a cause of pediatric septic arthritis of joints outside the pelvis and in the absence of coincident bacteremia. Outcome of pediatric septic arthritis is generally excellent; indwelling catheters impose a rare but real risk of secondary sepsis.