We are in the unique position to know many, but not all (yet), of the “points of sale” – restaurants and grocery stores. Having over 100 clients allows us to dig deep into their purchase history and consumption history. We have already determined clusters of illnesses linked to Panera, Texas Roadhouse, Red Lobsters and Papa Murphy’s. We also have identified a processor – Freshway. We have reached out to several other retailers, suppliers, processors and growers to ask (first nicely and then with a subpoena) if they will cooperate or not. We will continue our efforts and share what we find with the FDA and the public.
I will not complain here – again – why the FDA refuses to name those involved – from farms, distributors, processors and retailers (stores and restaurants). But you can read my thoughts here.
Directly from the FDA:
What does this traceback diagram (Redacted) tell us?
It says that there isn’t a simple or obvious explanation for how this outbreak occurred within the supply chain. If the explanation was as simple as a single farm, or a single processor or distributor, we would have already figured that out. The traceback diagram does show us that the contamination with E. coli O157:H7 was unlikely to have happened near the end of the supply chain (such as at a distributor) because there are no common distributors among the places that received and sold or served contaminated lettuce. The contamination likely happened at, or close to, the Yuma growing area.
Our task now is to investigate what happened. We are actively evaluating a number of theories about how romaine lettuce grown on multiple farms in the same growing region could have become contaminated around the same time. It’s possible that contamination occurred on multiple farms at once, through some sort of environmental contamination (e.g., irrigation water, air/dust, water used for pesticide application, animal encroachment). Another possibility is that it happened just after the lettuce left the farm. We are examining all possibilities and as we investigate we learn more about a potential common source we will communicate this information with growers and consumers. But the source and mode of contamination may remain difficult to identify.
Our efforts are complicated by the fact that romaine lettuce is a perishable commodity with a short shelf life of a couple of weeks. None of the lettuce that likely made people sick was available for testing because of the time between the incubation period of E. coli O157:H7 (the time between exposure to the lettuce and the onset of illness) and the time it takes to seek health care and collect specimens from ill people, test those specimens, report the illnesses to public health officials, fingerprint the pathogen to make sure it is part of the outbreak, and interview the ill people to identify where and when they were exposed. By that time, the lettuce they ate which could have made them ill is long gone.