The U.S. Food and Drug Administration, along with the Centers for Disease Control and Prevention (CDC) and state and local partners, investigated a multistate outbreak of E. coli O157:H7 illnesses linked to romaine lettuce from the Yuma growing region.

What was the Problem and What was Done?

On April 4, 2018 FDA learned about a cluster of E. coli O157:H7 infections in two states and on April 5, 2018 a new cluster was reported in multiple states. In the following weeks, the FDA, CDC, and state partners worked together to collect additional information and conduct traceback activities to identify a food item of interest.

O157:H7 infections in two states and on April 5, 2018 a new cluster was reported in multiple states. In the following weeks, the FDA, CDC, and state partners worked together to collect additional information and conduct traceback activities to identify a food item of interest. On April 10, 2018 the FDA publicly communicated about the outbreak, but was unable to identify a food source. The agency recommended that consumers practice safe food handling and preparation and to consult a health care provider if they think they might have symptoms of E. coli infection.

infection. Interviews with ill people allowed health partners to identify chopped romaine from the Yuma growing region as the likely source of contamination on April 13, 2018.

April 16, 2018 was the final day of romaine harvesting in the Yuma growing region, however at the time chopped romaine had just been identified as the likely source allowing the traceback investigation to begin and at this point, no specific farms in the Yuma region had been identified. FDA did not receive confirmation of the final harvest date until May 2, 2018.

On April 19, 2018, Alaska health partners announced that eight persons with E. coli O157:H7 infections from a correctional facility have been confirmed as part of the outbreak. These individuals ate whole-head romaine lettuce from the Yuma growing region. Following this announcement, the FDA advised consumers to avoid all romaine lettuce from the Yuma growing region. This region generally supplies romaine lettuce to the U.S. during November-March each year. In the following weeks FDA continued its traceback investigation, part of which was able to trace the Alaskan correctional facility back to a single farm, which was released on April 27, 2018.

O157:H7 infections from a correctional facility have been confirmed as part of the outbreak. These individuals ate whole-head romaine lettuce from the Yuma growing region. Following this announcement, the FDA advised consumers to avoid all romaine lettuce from the Yuma growing region. This region generally supplies romaine lettuce to the U.S. during November-March each year. In the following weeks FDA continued its traceback investigation, part of which was able to trace the Alaskan correctional facility back to a single farm, which was released on April 27, 2018. On May 2, 2018 the FDA received confirmation from the Arizona Leafy Greens Marketing Agreement that romaine lettuce was no longer being produced and distributed from the Yuma growing region, reducing the potential for exposure to contaminated product. At that time, due to the 21-day shelf life, we could not be certain that romaine lettuce from that region was no longer in the supply chain.

On May 31, 2018 the FDA released a blog with updated information on our ongoing traceback investigation (for additional information, visit FDA Update on Traceback Related to the E. coli O157:H7 Outbreak Linked to Romaine Lettuce). The FDA is working closely with federal, state, and local partners on an ongoing traceback investigation to determine the source of romaine lettuce supplied to ill consumers. In a typical traceback effort, CDC and the FDA identify clusters of people who became ill, especially in different geographical regions and work to trace the food eaten by those made ill to a common source. For this outbreak investigation, we have been able to identify romaine lettuce as the common food source. Romaine products that would have caused illness were no longer available at exposure locations, making it difficult to determine production lots of concern. In addition, we have found that a single production lot may contain romaine from multiple ranches, which makes the traceback more challenging. We are working with federal and state partners and companies as quickly as possible to collect, review and analyze hundreds of records in an attempt to traceback the source of the contaminated romaine lettuce. To date, the available information indicates that romaine lettuce from the Yuma growing region is the source of the current outbreak of E. coli O157:H7 infections, and was supplied to restaurants and retailers through multiple processors, grower/shipper companies, and farms. The information we have collected indicates that the illnesses associated with this outbreak cannot be explained by a single grower, harvester, processor, or distributor. While traceback continues, FDA will focus on trying to identify factors that contributed to contamination of romaine across multiple supply chains. The agency is examining all possibilities, including that contamination may have occurred at any point along the growing, harvesting, packaging, and distribution chain before reaching consumers. (for additional information, visit FDA Update on Traceback Related to the E. coli O157:H7 Outbreak Linked to Romaine Lettuce). The traceback investigation is ongoing and additional information will be provided as it becomes available.

O157:H7 Outbreak Linked to Romaine Lettuce). From June 4 - June 8, 2018 sampling for the environmental assessment was conducted in the Yuma growing region.

On June 28, 2018 the CDC announced that the outbreak has ended. In addition, the FDA and CDC announced preliminary sample results from the environmental assessment of the Yuma growing region.

What is E. coli O157:H7?

E.coli O157:H7 is a Shiga-toxin-producing (STEC) E. coli. The symptoms of STEC infections vary for each person but often include severe stomach cramps and bloody diarrhea. If there is fever, it is usually not very high (less than 101 degrees Fahrenheit/less than 38.5 degrees Celsius). Most people get better within 5–7 days. Some infections are very mild, but others are severe or even life-threatening.

Around 5–10 percent of those who are diagnosed with STEC infection develop a potentially life-threatening complication, known as hemolytic uremic syndrome (HUS).

Symptoms of HUS include fever, abdominal pain, feeling very tired, decreased frequency of urination, small unexplained bruises or bleeding, and pallor. Most people with HUS recover within a few weeks, but some suffer permanent damage or die. People who experience these symptoms should seek emergency medical care immediately. Persons with HUS should be hospitalized because their kidneys may stop working (acute renal failure), but they may also develop other serious problems such as hypertension, chronic kidney disease, and neurologic problems.

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Who is at Risk?

People of any age can become infected with STEC. Children under the age of 5 years, adults older than 65, and people with weakened immune systems are more likely than others to develop severe illness, including HUS, but even healthy older children and young adults can become seriously ill.

What Do Restaurants and Retailers Need To Do?

Retailers, restaurants, and other food service operators should always take steps to avoid the cross contamination of cutting surfaces and utensils through contact with potentially contaminated products. Retailers, restaurants, and other food service operators should always take steps to adequately control the temperature of cut leafy greens and to avoid cross contamination of cutting surfaces and utensils through contact with potentially contaminated products. To prevent cross contamination, you should follow the steps below:

Wash and sanitize display cases and refrigerators where potentially contaminated products were stored.

Wash and sanitize cutting boards, surfaces, and utensils used to prepare, serve, or store potentially contaminated products.

Wash hands with hot water and soap following the cleaning and sanitation process.

In accordance with the FDA Food Code 2017, cut leafy greens, including romaine lettuce, require time/temperature control for safety and should be refrigerated at 41°F or lower.

Regular frequent cleaning and sanitizing of food contact surfaces and utensils used in food preparation may help to minimize the likelihood of cross-contamination.

What Do Consumers Need To Do?

Consumers should always practice safe food handling and preparation measures. It is recommended that they wash hands, utensils, and surfaces with hot, soapy water before and after handling food.

For refrigerators and other food preparation surfaces and food cutting utensils that may have come in contact with contaminated foods, it is very important that the consumers thoroughly clean these areas and items.

Consumers should follow these simple steps:

Wash the inside walls and shelves of the refrigerator, cutting boards and countertops; then sanitize them with a solution of one tablespoon of chlorine bleach to one gallon of hot water; dry with a clean cloth or paper towel that has not been previously used.

Wash hands with warm water and soap for at least 20 seconds before and after handling food.

Wipe up spills in the refrigerator immediately and clean the refrigerator regularly.

Always wash hands with hot, soapy water following the cleaning and sanitization process.

Persons who think they might have become ill from eating potentially contaminated foods should consult their health care provider.