FDA, CDC, state and local agencies, in partnership with Canadian health officials, once again are investigating a multistate outbreak of E. coli O157:H7 that has sickened at least 50 people in the U.S. and Canada, 19 of whom have been hospitalized. The illnesses appear to be linked to romaine lettuce, but the exact source is unknown and remains under investigation.
In a dire warning to consumers, the CDC announced that romaine lettuce is unsafe to eat in any form, whether chopped, whole head or part of a mix. CDC is directing consumers to throw away any romaine lettuce in their possession. In addition, CDC is advising restaurants not to serve it, stores not to sell it, and people not buy it, no matter where or when the lettuce was grown.
In short, all romaine lettuce should be discarded.
As food industry lawyers, we track these outbreaks closely. And, this is now the third high profile E. coli outbreak tied to romaine lettuce in the last 12-months. The first of the three, which occurred in late 2017, appears to be related to the current outbreak. The second was in spring 2018. Notably, none of these three outbreaks have been traced to a definitive source. Investigators believe the 2017 outbreak was caused by contaminated products were from multiple firms located in Arizona, California, and Mexico. These happen to be the geographic locations where most North American romaine lettuce is grown. The source of last spring’s outbreak is believed to be the Yuma Valley growing region.
In terms of the possible relationship to the 2017 outbreak, genetic fingerprinting has reportedly shown a match between the current E. coli O157:H7 strain and the 2017 strain. There are other striking similarities as well. As previously mentioned, the late 2017 outbreak was also tied to romaine lettuce (and leafy greens). The outbreak timeframes are also quite similar, with 2017 cases occurring between November 5 and December 12.
The FDA is in the midst of conducting a traceback investigation to determine the source of the romaine lettuce eaten by people sickened in the current outbreak, and additional samples are currently undergoing laboratory analysis that may reveal additional source information.
The fact remains, however, that traceability of products like lettuce can be extraordinarily difficult for several reasons. One reason is that the limited shelf life of lettuce means that packaging is rarely available by time the illness is identified. Even where packaging is available, it is often of limited utility because lettuce products are often repackaged multiple times as they proceed through the supply chain. Consequently, even non-contaminated products are often implicated. Additionally, lettuce products are often comingled, and lettuce from multiple farms can comprise a single production lot, making it very challenging to narrow down original source. Also, people who eat lettuce eat it often, and thus have multiple possible exposures.
Despite the number of outbreaks, lettuce growers, brokers, and others throughout the supply chain have been working hard to enhance food safety controls and improve traceability. Emerging technologies—such as blockchain—will likely result in significant improvements in the future.
Nonetheless, for the time being, traceability is only one of many challenges faced by the industry. Romaine, obviously, is grown in the dirt. Dirt, as we all know, is dirty. Moreover, lettuce, unlike most other vectors, does not undergo a kill step, i.e., cooking. As a result, it is likely that similar outbreaks will continue to periodically occur for the foreseeable future. As such, companies up and down the supply chain should take proactive steps to protect their business, brand, and most importantly, their customers.