title: Community-onset methicillin-resistant Staphylococcus aureus associated with antibiotic use and the cytotoxin Panton-Valentine leukocidin during a furunculosis outbreak in rural Alaska.
abstract: BACKGROUND
  Community-onset methicillin-resistant Staphylococcus aureus (CO-MRSA) reports are increasing, and infections often involve soft tissue. During a CO-MRSA skin infection outbreak in Alaska, we assessed risk factors for disease and whether a virulence factor, Panton-Valentine leukocidin (PVL), could account for the high rates of MRSA skin infection in this region.
  
  
  METHODS
  We conducted S. aureus surveillance in the outbreak region and a case-control study in 1 community, comparing 34 case patients with MRSA skin infection with 94 control subjects. An assessment of traditional saunas was performed. S. aureus isolates from regional surveillance were screened for PVL genes by use of polymerase chain reaction, and isolate relatedness was determined by use of pulsed-field gel electrophoresis (PFGE).
  
  
  RESULTS
  Case patients received more antibiotic courses during the 12 months before the outbreak than did control subjects (median, 4 vs. 2 courses; P=.01) and were more likely to use MRSA-colonized saunas than were control subjects (44% vs. 13%; age-adjusted odds ratio, 4.6; 95% confidence interval, 1.7-12). The PVL genes were present in 110 (97%) of 113 MRSA isolates, compared with 0 of 81 methicillin-susceptible S. aureus isolates (P<.001). The majority of MRSA isolates were closely related by PFGE.
  
  
  CONCLUSIONS
  Selective antibiotic pressure for drug-resistant strains carrying PVL may have led to the emergence and spread of CO-MRSA in rural Alaska.
authors.affiliation: Arctic Investigations Program, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Anchorage, Alaska 99508, USA.
authors.forename: Henry C
authors.initials: HC
authors.lastname: Baggett
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Hennessy
authors.forename: Karen
authors.initials: K
authors.lastname: Rudolph
authors.forename: Dana
authors.initials: D
authors.lastname: Bruden
authors.forename: Alisa
authors.initials: A
authors.lastname: Reasonover
authors.forename: Alan
authors.initials: A
authors.lastname: Parkinson
authors.forename: Rachel
authors.initials: R
authors.lastname: Sparks
authors.forename: Rodney M
authors.initials: RM
authors.lastname: Donlan
authors.forename: Patricia
authors.initials: P
authors.lastname: Martinez
authors.forename: Kanokporn
authors.initials: K
authors.lastname: Mongkolrattanothai
authors.forename: Jay C
authors.initials: JC
authors.lastname: Butler
mesh_terms: D000293:Adolescent; D000328:Adult; D000413:Alaska / Q000453:epidemiology; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D001427:Bacterial Toxins; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000382:microbiology; D004196:Disease Outbreaks; D005098:Exotoxins / Q000378:metabolism; D005260:Female; D005667:Furunculosis / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007956:Leukocidins / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008712:Methicillin / Q000494:pharmacology / Q000627:therapeutic use; D016106:Methicillin Resistance; D011159:Population Surveillance; D012307:Risk Factors; D012424:Rural Population; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin; D008712:Methicillin