Comparative severity of pediatric osteomyelitis attributable to methicillin-resistant versus methicillin-sensitive Staphylococcus aureus.
BACKGROUND
Staphylococcus aureus remains the most common etiology of hematogenous osteomyelitis in children. Recently emerged virulent strains of methicillin-resistant S. aureus (MRSA) strains now predominate. It remains uncertain whether these pathogens cause a measurably more severe illness than methicillin-sensitive strains.


METHODS
We reviewed records of 97 pediatric patients with hematogenous osteomyelitis of varying etiologies to determine whether there were significant differences among the groups in terms of predetermined measures of disease severity. These measures included degree and duration of elevated temperature, acute-phase reactants, length of hospitalization, the number of surgical procedures required, and long-term sequelae.


RESULTS
Differences in the clinical course of illness were observed. Patients with MRSA had a significant increase in degree and duration of elevated temperature (P = 0.0001 for both), acute-phase reactant measures (white blood cell count, P = 0.0001; C-reactive protein, P = 0.0058; erythrocyte sedimentation rate, P = 0.0046), initial length of hospital stay (P = 0.0001), and surgical interventions (all procedures, P = 0.0001; therapeutic procedures, only P = 0.0002) as compared with patients with osteomyelitis caused by other bacterial pathogens and culture-negative osteomyelitis. A similar general pattern was observed when the analysis was restricted to culture-positive staphylococcal cases only.


CONCLUSIONS
Our results support the hypothesis that MRSA produces more severe bone infection and is likely to require more aggressive surgical and medical management.
Hawkshead
John J
JJ
Department of Epidemiology, Tulane University School of Public Health & Tropical Medicine, New Orleans, LA 70112, USA. jhawkshe@tulane.edu
Patel
Nimesh B
NB
Steele
Russell W
RW
Heinrich
Stephen D
SD
D000293:Adolescent; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D005260:Female; D005334:Fever / Q000209:etiology / Q000382:microbiology; D006801:Humans; D007223:Infant; D007902:Length of Stay; D007958:Leukocyte Count; D008297:Male; D016106:Methicillin Resistance; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification; D010019:Osteomyelitis / Q000382:microbiology / Q000503:physiopathology*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013203:Staphylococcal Infections / Q000382:microbiology / Q000503:physiopathology*; D013211:Staphylococcus aureus / Q000302:isolation & purification; D055815:Young Adult
D002097:C-Reactive Protein