The California Department of Health Services (CDHS) and California Department of Food and Agriculture (CDFA) conducted an investigation into the E. coli outbreak in September, 2006. CDHS and CDFA identified six children who had become ill with either E. coli O157:H7 or HUS and learned that all six had consumed Organic Pastures raw milk or colostrum in the days before becoming ill.
Pulsed field gel electrophoresis (PFGE), or “genetic fingerprinting” confirmed that five of the six children were infected with the same strain of E. coli; the sixth did not test positive for E. coli but had HUS.
An investigation at Organic Pastures led to the discovery that several cows were infected with E. coli O157:H7, although the strain was different from the outbreak strain. CDHS determined that unpasteurized dairy products from Organic Pastures were the likely source of the outbreak.