title: National Outbreak of Multidrug Resistant Salmonella Heidelberg Infections Linked to a Single Poultry Company.
abstract: OBJECTIVE
  This large outbreak of foodborne salmonellosis demonstrated the complexity of investigating outbreaks linked to poultry products. The outbreak also highlighted the importance of efforts to strengthen food safety policies related to Salmonella in chicken parts and has implications for future changes within the poultry industry.
  
  
  OBJECTIVE
  To investigate a large multistate outbreak of multidrug resistant Salmonella Heidelberg infections.
  
  
  METHODS
  Epidemiologic and laboratory investigations of patients infected with the outbreak strains of Salmonella Heidelberg and traceback of possible food exposures.
  
  
  METHODS
  United States. Outbreak period was March 1, 2013 through July 11, 2014.
  
  
  METHODS
  A case was defined as illness in a person infected with a laboratory-confirmed Salmonella Heidelberg with 1 of 7 outbreak pulsed-field gel electrophoresis (PFGE) XbaI patterns with illness onset from March 1, 2013 through July 11, 2014. A total of 634 case-patients were identified through passive surveillance; 200/528 (38%) were hospitalized, none died.
  
  
  RESULTS
  Interviews were conducted with 435 case-patients: 371 (85%) reported eating any chicken in the 7 days before becoming ill. Of 273 case-patients interviewed with a focused questionnaire, 201 (74%) reported eating chicken prepared at home. Among case-patients with available brand information, 152 (87%) of 175 patients reported consuming Company A brand chicken. Antimicrobial susceptibility testing was completed on 69 clinical isolates collected from case-patients; 67% were drug resistant, including 24 isolates (35%) that were multidrug resistant. The source of Company A brand chicken consumed by case-patients was traced back to 3 California production establishments from which 6 of 7 outbreak strains were isolated.
  
  
  CONCLUSIONS
  Epidemiologic, laboratory, traceback, and environmental investigations conducted by local, state, and federal public health and regulatory officials indicated that consumption of Company A chicken was the cause of this outbreak. The outbreak involved multiple PFGE patterns, a variety of chicken products, and 3 production establishments, suggesting a reservoir for contamination upstream from the production establishments. Sources of bacteria and genes responsible for resistance, such as farms providing birds for slaughter or environmental reservoir on farms that raise chickens, might explain how multiple PFGE patterns were linked to chicken from 3 separate production establishments and many different poultry products.
authors.affiliation: Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Laura
authors.initials: L
authors.lastname: Gieraltowski
authors.affiliation: California Department of Public Health, Gardena, Richmond, and Sacramento, California, United States of America.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Higa
authors.affiliation: California Department of Public Health, Gardena, Richmond, and Sacramento, California, United States of America.
authors.forename: Vi
authors.initials: V
authors.lastname: Peralta
authors.affiliation: Office of Public Health Science, Food Safety and Inspection Service, United States Department of Agriculture, Washington, DC, United States of America.
authors.forename: Alice
authors.initials: A
authors.lastname: Green
authors.affiliation: Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Colin
authors.initials: C
authors.lastname: Schwensohn
authors.affiliation: California Department of Public Health, Gardena, Richmond, and Sacramento, California, United States of America.
authors.forename: Hilary
authors.initials: H
authors.lastname: Rosen
authors.affiliation: California Emerging Infections Program, Oakland, California, United States of America.
authors.forename: Tanya
authors.initials: T
authors.lastname: Libby
authors.affiliation: Office of Public Health Science, Food Safety and Inspection Service, United States Department of Agriculture, Washington, DC, United States of America.
authors.forename: Bonnie
authors.initials: B
authors.lastname: Kissler
authors.affiliation: Washington State Department of Health, Olympia, Washington, United States of America.
authors.forename: Nicola
authors.initials: N
authors.lastname: Marsden-Haug
authors.affiliation: Oregon Public Health Division, Portland, Oregon, United States of America.
authors.forename: Hillary
authors.initials: H
authors.lastname: Booth
authors.affiliation: California Department of Public Health, Gardena, Richmond, and Sacramento, California, United States of America.
authors.forename: Akiko
authors.initials: A
authors.lastname: Kimura
authors.affiliation: Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Julian
authors.initials: J
authors.lastname: Grass
authors.affiliation: Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Amelia
authors.initials: A
authors.lastname: Bicknese
authors.affiliation: Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Beth
authors.initials: B
authors.lastname: Tolar
authors.affiliation: Office of Public Health Science, Food Safety and Inspection Service, United States Department of Agriculture, Washington, DC, United States of America.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Defibaugh-Chávez
authors.affiliation: Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Ian
authors.initials: I
authors.lastname: Williams
authors.affiliation: Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Matthew
authors.initials: M
authors.lastname: Wise
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011200:Poultry / Q000382:microbiology*; D012478:Salmonella Food Poisoning / Q000453:epidemiology*; D019779:Salmonella enterica / Q000187:drug effects / Q000472:pathogenicity*; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents