The three-state outbreak of E. coli O157:H7 linked to hazelnuts sickened at least eight people, the Centers for Disease Control and Prevention (CDC) reported late last week.
The CDC had previously reported 7 ill with the outbreak strain.
In its update on the outbreak investigation, the CDC said product tests by the Minnesota Department of Agriculture on in-shell hazelnuts, by the California Department of Public Health on mixed nuts that included unshelled hazelnuts, and by the Wisconsin Department of Health Services on mixed nuts that included unshelled hazelnuts all detected E. coli O157:H7 matching the outbreak strain.
Earlier epidemiologic investigations in Michigan, Minnesota and Wisconsin had traced the hazelnuts, most of which had been purchased from grocery store bulk bins, to a common distributor: DeFranco & Sons in Los Angeles.
DeFranco recalled its bulk and packaged in-shell hazelnuts on March 4. The company had distributed the nuts nationwide.
The CDC said four of people infected with the outbreak pathogen were from Wisconsin, three were from Minnesota and one was from Michigan. They ranged in age from 15 to 78. Six were male. Half of the case patients had illnesses so severe they were hospitalized, but none reported hemolytic uremic syndrome.
The onset of their illnesses ranged from Dec. 20, 2010 to Feb. 16, 2011. CDC believes this outbreak is now over, but said illnesses that occurred after March 17 might not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported.
Outbreak map from the Centers for Disease Control and Prevention