Clinical and molecular epidemiology of Staphylococcus aureus catheter-related bacteremia in children.
BACKGROUND
Staphylococcus aureus (SA) is an important cause of catheter-related bacteremia (CRB). The USA300 clone increasingly causes healthcare associated infections. We compared children with SA-CRB due to USA300 versus non-USA300 isolates and identified risk factors for complications.


METHODS
Children at Texas Children's Hospital (TCH) with SA-CRB were identified from a prospective S. aureus surveillance study. S. aureus isolates were characterized by methicillin susceptibility and pulsed field gel electrophoresis.


RESULTS
From August 2001 to October 2007, 112 children with a first episode of SA-CRB and corresponding isolates were identified. USA300 accounted for 21 isolates. Metastatic infection complicated 10.7% of cases and was associated with methicillin resistance. Other complications were recurrence (n = 16), death (n = 13), thrombosis (n = 9), and intravascular "cast" (n = 6). Four patients with non-USA300 SA-CRB had endocarditis. Prolonged bacteremia was more common in methicillin-resistant SA (12/29) than in methicillin-susceptible SA SA-CRB (14/83) (P = 0.007). Complications were more common in patients with bacteremia > or =4 days (16/26 [61.5%]) versus patients with bacteremia <4 days (25/86 [29%]) (P = 0.003). The complication rate was lower in patients who had the catheter removed <4 days (22.5%) versus patients whose catheter was removed > or =4 days after infection or not removed (44.4%) (P = 0.02). Children with USA300 versus non-USA300 isolates did not differ with respect to frequency or type of complications.


CONCLUSIONS
At Texas Children's Hospital, the USA300 clone caused 19% of initial SA-CRB episodes and was associated with methicillin resistance. Complications occurred in 36.6% of the patients and were associated with prolonged bacteremia and catheter removal > or =4 days after infection or failure to remove the catheter.
Carrillo-Marquez
Maria A
MA
Department of Pediatrics, Infectious Diseases Section, Baylor College of Medicine, Houston, TX, USA. mamarque@bcm.edu
Hulten
Kristina G
KG
Mason
Edward O
EO
Kaplan
Sheldon L
SL
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology; D015373:Bacterial Typing Techniques; D055499:Catheter-Related Infections / Q000453:epidemiology* / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008712:Methicillin / Q000494:pharmacology; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D013781:Texas
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D008712:Methicillin