Outbreak of Salmonella Wandsworth and Typhimurium infections in infants and toddlers traced to a commercial vegetable-coated snack food.
OBJECTIVE
Human outbreaks of Salmonella infection have been attributed to a variety of food vehicles. Processed snack foods are increasingly consumed by children. In May 2007, state and local health departments and the Centers for Disease Control and Prevention investigated human infections from Salmonella Wandsworth, an extremely rare serotype.


METHODS
Serotyping and pulsed-field gel electrophoresis were used to identify outbreak-associated illnesses. Food history questionnaires and open-ended interviews were used to generate exposure hypotheses. A nationwide case-control study was conducted to epidemiologically implicate a source. Public health laboratories cultured implicated product from patient homes and retail stores.


RESULTS
Sixty-nine patients from 23 states were identified; 93% were aged 10 months to 3 years. Eighty-one percent of child patients had bloody diarrhea; 6 were hospitalized. No deaths were reported. The case-control study strongly associated illness with a commercial puffed vegetable-coated ready-to-eat snack food (mOR = 23.3, P = 0.0001), leading to a nationwide recall. Parents of 92% of interviewed case-children reported that children consumed the food during the week before their illness began; 43% reported daily consumption. Salmonella Wandsworth, 3 additional Salmonella serotypes and Chronobacter (formerly Enterobacter) sakazaki were all cultured from this product, leading to the identification of 18 human outbreak-related Salmonella Typhimurium illnesses.


CONCLUSIONS
This report documents a nationwide outbreak associated with a commercial processed ready-to-eat snack food. Cases occurred primarily in infants and toddlers, many of whom frequently consumed the food. Measures are needed to ensure that ingredients added to ready-to-eat foods after the final lethal processing step are free of pathogens.
Enteric Diseases Epidemiology Branch, Division of Foodborne, Bacterial, and Mycotic Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30306, USA. msotir@cdc.gov
Mark J
MJ
Sotir
Gwen
G
Ewald
Akiko C
AC
Kimura
Jeffrey I
JI
Higa
Anandi
A
Sheth
Scott
S
Troppy
Stephanie
S
Meyer
R Michael
RM
Hoekstra
Jana
J
Austin
John
J
Archer
Mary
M
Spayne
Elizabeth R
ER
Daly
Patricia M
PM
Griffin
D000328:Adult; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D005260:Female; D005506:Food Contamination / Q000032:analysis; D005516:Food Microbiology; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D057051:Product Recalls and Withdrawals; D012475:Salmonella / Q000302:isolation & purification*; D012478:Salmonella Food Poisoning / Q000453:epidemiology* / Q000382:microbiology; D012486:Salmonella typhimurium / Q000302:isolation & purification; D014481:United States / Q000453:epidemiology