title: Alfalfa seed decontamination in a Salmonella outbreak.
abstract: Based on in vitro data, the U.S. Food and Drug Administration recommends chemical disinfection of raw sprout seeds to reduce enteric pathogens contaminating the seed coats. However, little is known about the effectiveness of decontamination at preventing human disease. In 1999, an outbreak of Salmonella enterica serotype Mbandaka occurred in Oregon, Washington, Idaho, and California. Based on epidemiologic and pulsed-field gel electrophoresis evidence from 87 confirmed cases, the outbreak was linked to contaminated alfalfa seeds grown in California's Imperial Valley. Trace-back and trace-forward investigations identified a single lot of seeds used by five sprout growers during the outbreak period. Cases of salmonellosis were linked with two sprout growers who had not employed chemical disinfection; no cases were linked to three sprout growers who used disinfection. This natural experiment provides empiric evidence that chemical disinfection can reduce the human risk for disease posed by contaminated seed sprouts.
authors.affiliation: Oregon Department of Human Services, Portland, Oregon, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Gill
authors.forename: William E
authors.initials: WE
authors.lastname: Keene
authors.forename: Janet C
authors.initials: JC
authors.lastname: Mohle-Boetani
authors.forename: Jeff A
authors.initials: JA
authors.lastname: Farrar
authors.forename: Patti L
authors.initials: PL
authors.lastname: Waller
authors.forename: Christine G
authors.initials: CG
authors.lastname: Hahn
authors.forename: Paul R
authors.initials: PR
authors.lastname: Cieslak
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003666:Decontamination; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005516:Food Microbiology; D006801:Humans; D007223:Infant; D008297:Male; D000455:Medicago sativa / Q000382:microbiology*; D008875:Middle Aged; D015205:Northwestern United States / Q000453:epidemiology; D012480:Salmonella Infections / Q000453:epidemiology* / Q000382:microbiology; D019779:Salmonella enterica / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity