title: A national outbreak of Salmonella serotype Tennessee infections from contaminated peanut butter: a new food vehicle for salmonellosis in the United States.
abstract: BACKGROUND
  Salmonella serotype Tennessee is a rare cause of the estimated 1 million cases of salmonellosis occurring annually in the United States. In January 2007, we began investigating a nationwide increase in Salmonella Tennessee infections.
  
  
  METHODS
  We defined a case as Salmonella Tennessee infection in a patient whose isolate demonstrated 1 of 3 closely related pulsed-field gel electrophoresis patterns and whose illness began during the period 1 August 2006 through 31 July 2007. We conducted a case-control study in 22 states and performed laboratory testing of foods and environmental samples.
  
  
  RESULTS
  We identified 715 cases in 48 states; 37% of isolates were from urine specimens. Illness was associated with consuming peanut butter more than once a week (matched odds ratio [mOR], 3.5 [95% confidence interval {95% CI}, 1.4-9.9]), consuming Brand X peanut butter (mOR, 12.1 [95% CI, 3.6-66.3]), and consuming Brand Y peanut butter (mOR, 9.1 [95% CI, 1.0-433]). Brands X and Y were produced in 1 plant, which ceased production and recalled products on 14 February 2007. Laboratories isolated outbreak strains of Salmonella Tennessee from 34 Brands X and Y peanut butter jars and 2 plant environmental samples.
  
  
  CONCLUSIONS
  This large, widespread outbreak of salmonellosis is the first linked to peanut butter in the United States; a nationwide recall resulted in outbreak control. Environmental contamination in the peanut butter plant likely caused this outbreak. This outbreak highlights the risk of salmonellosis from heat-processed foods of nonanimal origin previously felt to be low risk for Salmonella contamination.
authors.affiliation: Division of Foodborne, Bacterial, and Mycotic Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. asheth@cdc.gov
authors.forename: Anandi N
authors.initials: AN
authors.lastname: Sheth
authors.forename: Mike
authors.initials: M
authors.lastname: Hoekstra
authors.forename: Nehal
authors.initials: N
authors.lastname: Patel
authors.forename: Gwen
authors.initials: G
authors.lastname: Ewald
authors.forename: Cathy
authors.initials: C
authors.lastname: Lord
authors.forename: Carmen
authors.initials: C
authors.lastname: Clarke
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Villamil
authors.forename: Katherine
authors.initials: K
authors.lastname: Niksich
authors.forename: Cheryl
authors.initials: C
authors.lastname: Bopp
authors.forename: Thai-An
authors.initials: TA
authors.lastname: Nguyen
authors.forename: Donald
authors.initials: D
authors.lastname: Zink
authors.forename: Michael
authors.initials: M
authors.lastname: Lynch
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D010367:Arachis / Q000382:microbiology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005516:Food Microbiology; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D011634:Public Health; D012475:Salmonella / Q000145:classification / Q000302:isolation & purification; D012478:Salmonella Food Poisoning / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D014481:United States / Q000453:epidemiology