Work

Alfalfa Seed Decontamination inSalmonellaOutbreak

Year: 2003

Type: article

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. MethodsWe defined case-patients as persons with culture-confirmed S. Mbandaka infection and onset of acute illness from January 1 to April 15, 1999.Cases were excluded if they were subsequently shown to have a pulsed field gel electrophoresis (PFGE) pattern that differed from the outbreak pattern.If the illness onset date was unknown, the specimen collection date minus 2 days was used instead.To generate hypotheses about potential exposure vehicles, ODHS conducted open-ended interviews with the first 10 474

Source: Emerging infectious diseases

DOI: 10.3201/eid0904.020519