The US Centers for Disease Control and Prevention (CDC) is collaborating with state health officials and the FDA to investigate a multistate outbreak of Listeria monocytogenes infections that may be associated with frozen vegetables produced by CRF Frozen Foods of Pasco, Washington.
The outbreak has affected at least eight people from three states since 13 September 2013. All eight of the reported cases were hospitalised and two subsequently died, although listeriosis was not considered to be a cause of death for either person. The outbreak was recognised in March 2016 and genetic techniques, such as whole genome sequencing (WGS), and the PulseNet database are being used to try and identify other illnesses that may be linked.
Interviews with three of the people affected by the outbreak revealed that two of them had eaten Organic by Nature brand frozen vegetables in the month before they became ill. This brand is produced by CRF Frozen Foods. Listeria has also been isolated from other brands of frozen vegetables produced by CRF Frozen Foods and WGS analysis has shown a close genetic relationship between these isolates and those from ill people.
CRF Frozen Foods recalled various products on 23 April and then expanded the recall to include all organic and traditional frozen vegetable and fruit products processed at its Pasco facility since 1 May 2014. These products were sold in plastic bags under a variety of brand names nationwide and in Canada.