E coli Outbreak Linked with Romaine Lettuce Teaches Important Lesson in Food Safety

The Centers for Disease Control and Prevention (CDC) and the US Food and Drug Administration (FDA) recently announced that the deadly multistate outbreak of Escherichia coli (E. coli) O157:H7 infections linked with romaine lettuce, which has been referred to as the largest E. coli outbreak since 2006, is officially over. Although questions remain, scientific advances led to breakthroughs that would not have been possible just a few years ago.

The final case count update was released on June 28, 2018, and reported 210 total cases spanning 36 states; five individuals died from their infections. Of the 210 cases, 96 individuals required hospitalization for their infections. Furthermore, 27 individuals went on to develop hemolytic uremic syndrome.

In a recent statement, FDA commissioner Scott Gottlieb, MD, stressed that although the outbreak is declared to be over, there is more work to be done to further understand it.

“The FDA, CDC, and Arizona state officials continue to analyze samples from the Yuma region collected in early June and initial results are starting to become available,” he wrote. “Several environmental samples of canal water in the area have been found to contain E. coli O157:H7 that genetically match the strain of bacteria that caused the outbreak.”

He added that there are still many questions pertaining to the positive samples, such as how the outbreak strain even got into the body of water and how this led to the contamination of romaine lettuce growing in multiple farms.

“We, along with our partners, will continue to assess these findings, their meanings, and determine what additional efforts may help us better understand this outbreak,” he stressed. “We are committed to continuing to share updates on our progress.”

Despite the many questions that still remain, Dr. Gottlieb stressed that scientific advances made by way of the different technologies now available have led to several breakthroughs throughout the investigation and it is because of these advances that health officials are able to detect and resolve outbreaks much more efficiently.

Because the methods to detect these outbreaks have strengthened, it makes sense that more outbreaks are being reported, which makes it difficult to determine if the number of outbreaks is increasing or decreasing and if food safety practices are getting stronger or weaker.

The CDC estimates that a staggering 50 million individuals are affected by food-borne illnesses each year, which equates to about 1 in 6 Americans, according to Dr. Gottlieb. He added that of those individuals, 128,000 will require hospitalization and about 3,000 will lose their lives.

“These numbers are tragically high,” he stressed. “While we know we can’t stop food-borne illness completely, these numbers underscore the need for us to do much more. We need to take additional steps, and do it faster, to improve the safety of our food supply.”

One of the most important tools used to strengthen outbreak detection and response efforts is whole genome sequencing (WGS), a technique that is used to determine the entire genetic blueprint of a food-borne pathogen. Through WGS, officials are able to link illnesses in different individuals living in different locations to not only uncover outbreaks but their source as well.

“Recognizing the value of WGS to more precisely pinpoint the source of food-borne outbreaks, we are joining our partners in ensuring this technology is made more available to states,” Dr. Gottlieb added. The first distributed network of food laboratories, GenomeTrakr, is also utilizing WGS to provide sequencing capacity in state food testing labs.

Another effort the FDA has been making to avoid food-borne outbreaks is to leverage recall authorities to remove potentially contaminated products from the market quickly and efficiently. The FDA will be releasing new guidance on additional information they plan on collecting and making available as recall notifications are issued.

Dr. Gottlieb also mentioned the ongoing implementation of the FDA Food Safety Modernization Act (FSMA) which works to shift the national focus off of outbreak response and on to prevention efforts.

“We must never settle for just a small number of outbreaks or grow comfortable with food-borne illness as a fact of life,” he stressed. “We may not stop every outbreak from occurring. But our goal should be to try.”