Three-year surveillance of community-acquired Staphylococcus aureus infections in children.
BACKGROUND
Methicillin-resistant Staphylococcus aureus (MRSA) isolates are increasingly frequent causes of skin and soft-tissue infections or invasive infections in many communities.


METHODS
Prospective surveillance for community-acquired S. aureus infections at Texas Children's Hospital was initiated on 1 August 2001. Infections meeting the definition of community-acquired were identified. Demographic and clinical data were collected. Antibiotic susceptibilities, including inducible resistance to macrolide, lincosamide, and streptogramin B (MLSB), were determined in the clinical microbiology laboratory with the methodology of the NCCLS. All data were entered into a computer database. Data were analyzed by chi2 tests.


RESULTS
From 1 August 2001 to 31 July 2004, the percentage of community-acquired S. aureus isolates that were methicillin resistant increased from 71.5% (551 of 771 isolates) in year 1 to 76.4% (1193 of 1562 isolates) in year 3 (P = .008). The number of both community-acquired MRSA (CA-MSRA) isolates and community-acquired methicillin-susceptible S. aureus (CA-MSSA) isolates increased yearly, but the rate of increase was greater for the CA-MRSA isolates. Among the CA-MRSA isolates, 2542 (95.6%) were obtained from children with skin and soft-tissue infections, and 117 (4.4%) were obtained from children with invasive infections. Overall, 62% of children with CA-MRSA isolates and 53% of children with CA-MSSA isolates were admitted to the hospital (P = .0001). The rate of clindamycin resistance increased significantly for both CA-MRSA isolates (P = .003) and CA-MSSA isolates (P = .00003) over the 3 years. MLSB inducible resistance was found in 27 (44%) of 62 clindamycin-resistant CA-MSSA isolates, compared with 6 (4.5%) of 132 clindamycin-resistant CA-MRSA isolates (P < .000001).


CONCLUSIONS
CA-MRSA isolates account for an increasing percentage and number of infections at Texas Children's Hospital. Clindamycin resistance increased among community-acquired S. aureus isolates. Community surveillance of community-acquired S. aureus infections is critical to determine the appropriate empiric antibiotic treatment for either local or invasive infections.
Kaplan
Sheldon L
SL
Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA. skaplan@bcm.tmc.edu
Hulten
Kristina G
KG
Gonzalez
Blanca E
BE
Hammerman
Wendy A
WA
Lamberth
Linda
L
Versalovic
James
J
Mason
Edward O
EO
D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000382:microbiology*; D006801:Humans; D007223:Infant; D016106:Methicillin Resistance; D011159:Population Surveillance; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification*; D013997:Time Factors