title: Microbiology of skin and soft tissue infections in the age of community-acquired methicillin-resistant Staphylococcus aureus.
abstract: The objectives of this study were to determine the etiology of skin and soft-tissue infections (SSTIs) in a general population, and to describe patient characteristics, SSTI types, frequency of microbiologic testing, and the role of methicillin-resistant Staphylococcus aureus (MRSA) over time. Using electronic databases, we identified SSTI episodes and microbiologic testing among members of a large US health plan. Between 2006 and 2009, 648699 SSTI episodes were identified, of which 23% had a specimen, of which 15% were blood. A pathogen was identified in 58% of SSTI cultures. S. aureus was the most common pathogen (80% of positive cultures). Half of S. aureus isolates were MRSA. Among cellulitis and abscess episodes with a positive blood culture, 21% were methicillin-sensitive S. aureus, 16% were MRSA, 21% were beta-hemolytic streptococci and 28% were Gram negative bacteria. Between 1998 and 2009, the percentage of SSTIs for which a culture was obtained increased from 11% to 24%. In SSTI episodes with a culture-confirmed pathogen, MRSA increased from 5% in 1998 to 9% in 2001 to 42% in 2005, decreasing to 37% in 2009. These data can inform the choice of antibiotics for treatment of SSTIs.
authors.affiliation: Division of Research, Kaiser Permanente Medical Care Program, Northern California Region, Oakland, CA, USA. tom.ray@kp.org
authors.forename: G Thomas
authors.initials: GT
authors.lastname: Ray
authors.forename: Jose A
authors.initials: JA
authors.lastname: Suaya
authors.forename: Roger
authors.initials: R
authors.lastname: Baxter
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002481:Cellulitis / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012189:Retrospective Studies; D012867:Skin / Q000382:microbiology / Q000473:pathology; D018461:Soft Tissue Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology*; D013207:Staphylococcal Skin Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents