Skip to main content
          Skip to FDA Search
          Skip to in this section menu
          Skip to footer links


U.S. flagAn official website of the United States government

					Here’s how you know
          			Dot gov**The .gov means it’s official.**Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you're on a federal government site.
							      SSL**The site is secure.** The **https://** ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely. 
			U.S. Food and Drug Administration
				
        Search
            Menu
							
						Search FDA
									
									Submit search 
		Featured
							Contact FDA
	                FDA Guidance Documents
	                Recalls, Market Withdrawals and Safety Alerts
	                Press Announcements
	                Warning Letters
	                Advisory Committees
	                En Español

					Products
            Food
							Drugs
							Medical Devices
							Radiation-Emitting Products
							Vaccines, Blood, and Biologics
							Animal and Veterinary
							Cosmetics
							Tobacco ProductsTopics
            About FDA
							Combination Products
							Regulatory Information
							Safety
							Emergency Preparedness
							International Programs
							News and Events
							Training and Continuing Education
							Inspections and Compliance
							Science and ResearchInformation For
            Consumers
	            Patients
	            Industry
	            Health Professionals
	            Federal, State and Local Officials 
 In this section:

                CFSAN Constituent Updates

CFSAN Constituent Updates Home
          Food
          News & Events from CFSAN
          CFSAN Constituent Updates
          FDA Partners with the University of Arizona, Wellton-Mohawk Irrigation and Drainage District, and Yuma Area Leafy Greens Stakeholders to Enhance Food SafetyCFSAN Constituent Updates FDA Partners with the University of Arizona, Wellton-Mohawk Irrigation and Drainage District, and Yuma Area Leafy Greens Stakeholders to Enhance Food Safety
  
  	
    Subscribe to Email Updates
    Share
    Post
    Linkedin

    Email
    PrintConstituent Update

September 23, 2019

The U.S. Food and Drug Administration has launched a new initiative with support from the Arizona Department of Agriculture, and in conjunction with the University of Arizona Cooperative Extension, the Wellton-Mohawk Irrigation and Drainage District (WMIDD), and members of the Yuma area leafy greens industry to better understand the ecology of human pathogens in the environment in the Yuma agricultural region. This initiative will be a multi-year study which will focus on how these pathogens survive, move and possibly contaminate produce prior to harvest.

The launch of this initiative follows the largest *E.coli*O157:H7 outbreak in the United States since 2006. The outbreak, which was linked to romaine lettuce grown in the Yuma region, began in the spring of 2018 and resulted in 210 reported illnesses from 36 states, 96 hospitalizations, 27 cases of hemolytic uremic syndrome (HUS) and five deaths. In response,  FDA led an Environmental Assessment (EA) of the Yuma produce growing region in collaboration with Centers for Disease Control and Prevention (CDC), the Arizona Department of Agriculture (AZDA), WMIDD, and state partners from June through August 2018.

While the EA was useful in narrowing the scope of the outbreak, many questions remain unanswered regarding the specific origin of the pathogen, the environmental distribution, and potential reservoirs for the outbreak strain. The findings made clear that further collaboration among leafy greens stakeholders and FDA is needed to better understand potential sources of microbial contamination, the prevalence and persistence of human pathogens in the ecosystem near growing areas, and the best management practices to prevent future outbreaks from occurring.

Throughout this initiative, FDA will work in partnership with water quality, food safety, and agricultural experts from the University of Arizona Cooperative Extension, representatives from the WMIDD, and members of the Yuma area leafy greens industry. Research teams will be collecting and examining samples from the environment such as surface waters, canal sediment, and dust. The team will also be collecting scat samples to assess the impact that animal intrusion and native wildlife may have on the growing environment.

Shiga Toxin-Producing *E.coli*(STEC), of which*E.coli* O157:H7 is a strain, causes roughly 170,000 people to become ill every year. This generally happens through the consumption of contaminated food or water, or close contact with STEC-infected animals. Between 2009 and 2017, FDA and our partners at CDC identified 28 foodborne STEC outbreaks with known or suspected links to leafy greens. Like a lot of fresh produce, leafy greens are often eaten raw without a kill-step, such as cooking, that could eliminate pathogens that may be present.

The Yuma agricultural region, which encompasses Yuma County in Arizona and the Imperial Valley in California, is a leader in the production of leafy greens in the United States. The findings from this study will contribute new knowledge on how various environmental factors may influence bacterial persistence and distribution in this region, and how those factors may impact the risk of this commodity becoming contaminated. Results from this collaboration will lead to improved practices to prevent or mitigate food safety risks, and ultimately enhance the safety of produce grown in the region.

**For More Information**

Environmental Assessment of Factors Potentially Contributing to the Contamination of Romaine Lettuce Implicated in a Multi-State Outbreak of *E.coli*O157:H7
	Letter to State Agriculture Officials and the Leafy Greens Industry Concerning the Environmental Assessment
	FDA Investigating Multistate Outbreak of *E.coli*O157:H7 Infections Linked To Romaine Lettuce from Yuma Growing Region
	CDC Multistate Outbreak of*E.coli*O157:H7 Infections Linked to Romaine Lettuce (Final Update)

                                                                                  Content current as of:
      09/23/2019
              
              
Regulated Product(s)
		 Food & BeveragesCFSAN Constituent Updates
 Subscribe to CFSAN Constituent Updates
                        Get email updates delivered to your inbox.
    Enter your email address to subscribe:
 Footer Links
    FDA Archive
          About FDA
          Accessibility
      Visitor Information
          Website Policies / Privacy
          No FEAR Act
          Vulnerability Disclosure Policy
      FOIA
          HHS.gov
          USA.gov
    Contact FDA
      Follow FDA on Facebook
      Follow FDA on X
      Follow FDA on Instagram
      Follow FDA on LinkedIn
      View FDA videos on YouTube
      Subscribe to FDA RSS feeds
    FDA Homepage
    Contact Number
      1-888-INFO-FDA (1-888-463-6332) Back toTop