title: Are cases of Methicillin-resistant Staphylococcus aureus clonal complex (CC) 398 among humans still livestock-associated?
abstract: Methicillin-resistant Staphylococcus aureus (MRSA) of clonal complex (CC) 398 are widespread among pigs, cattle and poultry as well as among humans who have contact to these livestock animals. However, there is limited data on livestock-independent dissemination of MRSA CC398 in the general population.
  
  
  METHODS
  In this case-control study MRSA isolates derived (between July 2013 and June 2014) from patients of four hospitals located in a livestock-dense region were S. aureus protein A (spa) typed and risk factors for MRSA acquisition were assessed from patients colonized or infected with MRSA CC398 vs. other MRSA molecular types (MRSA non-CC398).
  
  
  RESULTS
  Of 384 patients, 21% were colonized with MRSA CC398. Contact with livestock (Odds Ratio (OR) 46.03) and residence directly on a pig farm (OR 12.82) were associated with MRSA CC398. Of 55 patients with MRSA CC398, 21 (38%) did not report direct livestock contact. Among the latter we identified several risk factors that could have facilitated indirect transmission, such as living on farms (without being farmer), private contact with known MRSA carriers or previous hospitalization.
  
  
  CONCLUSIONS
  This study suggests that MRSA CC398 is still mostly disseminated via direct contact to livestock. However, a substantial proportion of patients seem to acquire MRSA CC398 via other pathways.
authors.affiliation: Institute of Hygiene, University Hospital Münster, Robert-Koch-Str. 41, 48149 Münster, Germany; Christophorus-Kliniken GmbH, Hagenstraße 35, 48301 Nottuln, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Deiters
authors.affiliation: Christophorus-Kliniken GmbH, Hagenstraße 35, 48301 Nottuln, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Günnewig
authors.affiliation: Department of Medical Microbiology, University Medical Centre Groningen, University of Groningen, Hanzeplain 1, 9700 RB Groningen, The Netherlands.
authors.forename: Alexander W
authors.initials: AW
authors.lastname: Friedrich
authors.affiliation: Institute of Hygiene, University Hospital Münster, Robert-Koch-Str. 41, 48149 Münster, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Mellmann
authors.affiliation: Institute of Hygiene, University Hospital Münster, Robert-Koch-Str. 41, 48149 Münster, Germany. Electronic address: robin.koeck@ukmuenster.de.
authors.forename: Robin
authors.initials: R
authors.lastname: Köck
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000822:Animal Husbandry; D000818:Animals; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification* / Q000302:isolation & purification*; D008875:Middle Aged; D058889:Molecular Typing; D016273:Occupational Exposure; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology* / Q000635:transmission; D055815:Young Adult; D015047:Zoonoses / Q000382:microbiology / Q000635:transmission
keywords: CC398; Germany; Livestock; MRSA; Risk; spa