title: Multistate outbreak of listeriosis caused by imported cheese and evidence of cross-contamination of other cheeses, USA, 2012.
abstract: Listeria monocytogenes is a foodborne pathogen that can cause bacteraemia, meningitis, and complications during pregnancy. In July 2012, molecular subtyping identified indistinguishable L. monocytogenes isolates from six patients and two samples of different cut and repackaged cheeses. A multistate outbreak investigation was initiated. Initial analyses identified an association between eating soft cheese and outbreak-related illness (odds ratio 17·3, 95% confidence interval 2·0-825·7) but no common brand. Cheese inventory data from locations where patients bought cheese and an additional location where repackaged cheese yielded the outbreak strain were compared to identify cheeses for microbiological sampling. Intact packages of imported ricotta salata yielded the outbreak strain. Fourteen jurisdictions reported 22 cases from March-October 2012, including four deaths and a fetal loss. Six patients ultimately reported eating ricotta salata; another reported eating cheese likely cut with equipment also used for contaminated ricotta salata, and nine more reported eating other cheeses that might also have been cross-contaminated. An FDA import alert and US and international recalls followed. Epidemiology-directed microbiological testing of suspect cheeses helped identify the outbreak source. Cross-contamination of cheese highlights the importance of using validated disinfectant protocols and routine cleaning and sanitizing after cutting each block or wheel.
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: K E
authors.initials: KE
authors.lastname: Heiman
authors.affiliation: U.S. Food and Drug Administration,Silver Spring,MD,USA.
authors.forename: V B
authors.initials: VB
authors.lastname: Garalde
authors.affiliation: Allegheny County Health Department,Pittsburgh,PA,USA.
authors.forename: M
authors.initials: M
authors.lastname: Gronostaj
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Jackson
authors.affiliation: California Department of Food and Agriculture,Sacramento,CA,USA.
authors.forename: S
authors.initials: S
authors.lastname: Beam
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: L
authors.initials: L
authors.lastname: Joseph
authors.affiliation: Minnesota Department of Health,St Paul,MN,USA.
authors.forename: A
authors.initials: A
authors.lastname: Saupe
authors.affiliation: Maryland Department of Health and Mental Hygiene,Baltimore,MD,USA.
authors.forename: E
authors.initials: E
authors.lastname: Ricotta
authors.affiliation: New York City Department of Health and Hygiene,NY,New York,USA.
authors.forename: H
authors.initials: H
authors.lastname: Waechter
authors.affiliation: Virginia Department of Health,Richmond,VA,USA.
authors.forename: A
authors.initials: A
authors.lastname: Wellman
authors.affiliation: New Mexico Department of Health,Santa Fe,NM,USA.
authors.forename: M
authors.initials: M
authors.lastname: Adams-Cameron
authors.affiliation: District of Columbia Department of Health,Washington,DC,USA.
authors.forename: G
authors.initials: G
authors.lastname: Ray
authors.affiliation: U.S. Food and Drug Administration,Silver Spring,MD,USA.
authors.forename: A
authors.initials: A
authors.lastname: Fields
authors.affiliation: U.S. Food and Drug Administration,Silver Spring,MD,USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.affiliation: U.S. Food and Drug Administration,Silver Spring,MD,USA.
authors.forename: A
authors.initials: A
authors.lastname: Datta
authors.affiliation: U.S. Food and Drug Administration,Silver Spring,MD,USA.
authors.forename: L
authors.initials: L
authors.lastname: Burall
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: A
authors.initials: A
authors.lastname: Sabol
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Kucerova
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: E
authors.initials: E
authors.lastname: Trees
authors.affiliation: U.S. Food and Drug Administration,Silver Spring,MD,USA.
authors.forename: M
authors.initials: M
authors.lastname: Metz
authors.affiliation: U.S. Food and Drug Administration,Silver Spring,MD,USA.
authors.forename: P
authors.initials: P
authors.lastname: Leblanc
authors.affiliation: U.S. Food and Drug Administration,Silver Spring,MD,USA.
authors.forename: S
authors.initials: S
authors.lastname: Lance
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: P M
authors.initials: PM
authors.lastname: Griffin
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: R V
authors.initials: RV
authors.lastname: Tauxe
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases,Centers for Disease Control and Prevention,Atlanta,GA,USA.
authors.forename: B J
authors.initials: BJ
authors.lastname: Silk
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002611:Cheese / Q000382:microbiology*; D004196:Disease Outbreaks; D005260:Female; D005516:Food Microbiology; D005517:Foodborne Diseases / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D006801:Humans; D008089:Listeria monocytogenes / Q000145:classification / Q000302:isolation & purification*; D008088:Listeriosis / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D014481:United States / Q000453:epidemiology
keywords: Cheese; Listeria; contamination; outbreak