Investigation into Listeria outbreak linked to frozen vegetables over - CDC

A Listeria outbreak linked to frozen vegetables produced by CRF Frozen Foods has ended, according to the US Centers for Disease Control and Prevention (CDC).

At least 456 products were recalled related to the outbreak. CRF Frozen Foods recalled 358 products and around 98 others were recalled by firms that received CRF-recalled items (see here)

Nine people were reported from four states since September 13, 2013.

Listeriosis was considered to be a cause of death for one person in Connecticut. For the two deaths in Maryland and Washington, it was not considered to be the cause.

Contamination source unclear

The source of Listeria has not been identified.

In March, environmental samples collected by FDA from Oregon Potato Company, of Pasco, Washington, were found to be closely related genetically to eight of the isolates of ill people associated with the outbreak.

Oregon Potato Company recalled wholesale onion products, which led to downstream customer recalls. One of which publicly disclosed Oregon Potato Company as its product source.

The Ohio Department of Agriculture isolated Listeria monocytogenes in April from True Goodness by Meijer brand frozen organic white sweet cut corn and frozen organic petite green peas. Both were produced by CRF Frozen Foods.

Whole genome sequencing showed the L. monocytogenes isolated from the frozen corn was closely related genetically to eight bacterial isolates from ill people, and the L. monocytogenes isolate from the frozen peas was closely related to one isolate from another ill person.

Incident timeline

An FDA inspection in March of CRF Frozen Foods said the ‘materials and workmanship of equipment and utensils does not allow proper cleaning and maintenance’.

In April, CRF Frozen Foods ceased production at its Pasco, Washington facility and recalled 11 frozen vegetable products.

In May, the firm expanded its recall to include all of its frozen organic and traditional fruit and vegetable products manufactured or processed in its Pasco facility since May 1, 2014.

CRF Frozen Foods temporarily laid off 250 workers at the plant in the same month due to its closure but local media recently reported the firm is seeking federal approval to restart production.  

CDC said while the investigation is over people could continue to get sick because recalled products may still be freezers and be eaten.

Recalled products were distributed nationwide and in Canada under many different brand names, no illnesses were reported in Canada.

Listeria positive specimens were collected from September 13, 2013, to May 3, 2016. Three illnesses were reported this year.

Ill people ranged in age from 56 to 91 years. A total of 78% were female and all were hospitalized.