The CDC reports that eight people infected with the outbreak strains of Listeria monocytogenes have been reported from three states (California, Maryland and Washington) from September 2013 – March 2016. Ill people ranged in age from 56 to 86, with a median age of 76. Epidemiology and laboratory evidence available at this time indicates that frozen vegetables produced by CRF Frozen Foods of Pasco, Washington, and sold under various brand names are one likely source of illnesses in this outbreak. As discussed further below, CRF Frozen Foods has initiated a recall of certain products.
As part of a routine product sampling program the Ohio Department of Agriculture collected packages of frozen vegetable products from a retail location and isolated Listeria monocytogenes from True Goodness by Meijer brand frozen organic white sweet cut corn and frozen organic petite green peas. Both products were produced by CRF Frozen Foods.
Whole genome sequencing showed that the Listeria monocytogenes isolate from the frozen corn was closely related genetically to seven bacterial isolates from ill people, and the Listeria monocytogenes isolate from the frozen peas was closely related genetically to one isolate from an ill person. This close genetic relationship provides additional evidence that the people in this outbreak became ill from eating frozen vegetables produced by CRF Frozen Foods.
Based on the positive findings by the Ohio Department of Agriculture, on April 22, 2016, CRF recalled 11 frozen vegetable products because they may be contaminated with Listeria monocytogenes. On May 2, 2016, following a conversation between FDA, CDC and the firm, CRF Frozen Foods expanded its recall to include all of its frozen organic and traditional fruit and vegetable products manufactured or processed in CRF Frozen Foods’ Pasco facility since May 1, 2014. Approximately 358 consumer products sold under 42 separate brands were recalled.
Additionally, March 2016 environmental samples collected by FDA from Oregon Potato Company, located in Pasco, WA, were found to be closely related genetically to seven of the isolates of ill people associated with this outbreak. Based on this information, Oregon Potato Company voluntarily recalled wholesale onion products, which led to subsequent downstream customer recalls, one of which publicly disclosed Oregon Potato Company as its product source. FDA is working to identify other parts of the relevant supply chain that may have product relating to this outbreak.