title: Meticillin-resistant Staphylococcus aureus CC398 is an increasing cause of disease in people with no livestock contact in Denmark, 1999 to 2011.
abstract: Livestock constitutes a potential reservoir of meticillin-resistant Staphylococcus aureus isolates belonging to a recently derived lineage within clonal complex 398 (MRSA CC398-IIa). Since its discovery in the early 2000s, this lineage has become a major cause of human disease in Europe, posing a serious public health challenge in countries with intensive livestock production. To retrace the history of human colonisation and infection with MRSA CC398-IIa in Denmark, we conducted a nationwide, retrospective study of MRSA isolates collected from 1999 to 2011. Among 7,429 MRSA isolates screened, we identified 416 MRSA CC398-IIa isolates. Of these, 148 were from people with infections, including 51 from patients reporting no livestock exposure. The first cases of MRSA CC398-IIa infection in Denmark occurred in 2004. Subsequently, the incidence of MRSA CC398-IIa infection showed a linear annual increase of 66% from 2004 to 2011 (from 0.09 to 1.1 per 100,000 person-years). There were clear temporal and spatial relationships between MRSA CC398-IIa-infected patients with and without livestock exposure. These findings suggest substantial dissemination of MRSA CC398-IIa from livestock or livestock workers into the Danish community and underscore the need for strategies to control its spread both on and off the farm.
authors.affiliation: Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark.
authors.forename: Jesper
authors.initials: J
authors.lastname: Larsen
authors.forename: Andreas
authors.initials: A
authors.lastname: Petersen
authors.forename: Marit
authors.initials: M
authors.lastname: Sørum
authors.forename: Marc
authors.initials: M
authors.lastname: Stegger
authors.forename: Lieke
authors.initials: L
authors.lastname: van Alphen
authors.forename: Palle
authors.initials: P
authors.lastname: Valentiner-Branth
authors.forename: Lisbet Krause
authors.initials: LK
authors.lastname: Knudsen
authors.forename: Lars Stehr
authors.initials: LS
authors.lastname: Larsen
authors.forename: Beth
authors.initials: B
authors.lastname: Feingold
authors.forename: Lance Bradley
authors.initials: LB
authors.lastname: Price
authors.forename: Paal Skytt
authors.initials: PS
authors.lastname: Andersen
authors.forename: Anders Rhod
authors.initials: AR
authors.lastname: Larsen
authors.forename: Robert Leo
authors.initials: RL
authors.lastname: Skov
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000890:Anti-Infective Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D021821:Communicable Diseases, Emerging / Q000382:microbiology* / Q000635:transmission; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016106:Methicillin Resistance; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D015995:Prevalence; D012042:Registries; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D000890:Anti-Infective Agents
keywords: epidemiology; meticillin-resistant Staphylococcus aureus (MRSA) in animals; meticillin-resistant Staphylococcus aureus (MRSA) in humans; surveillance; typing; zoonotic infections