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microscopic image of E. coli bacteria

Background

Escherichia coli (E. coli) are mostly harmless bacteria that live in the intestines of people and animals and contribute to intestinal health. However, eating or drinking food or water contaminated with certain types of E. coli can cause mild to severe gastrointestinal illness. Some types of pathogenic (illness-causing) E. coli, such as Shiga toxin-producing E. coli (STEC), can be life-threatening. Different types of E. coli tend to contaminate different types of foods and water. Previous U.S. outbreaks of pathogenic E. coli have included leafy greens, sprouts, raw milk and cheeses, and raw beef and poultry.

Some wildlife, livestock, and humans are occasional carriers of pathogenic E. coli and can contaminate meats and food crops. Ruminant animals such as cattle, goats, sheep, deer or elk, as well as other animals such as pigs or birds are known carriers of pathogenic E. coli, such as STEC, and are often the pathway as to how STEC is introduced into the environment.

Fresh or raw produce like leafy greens can be particularly susceptible to E. coli that exists in the growing environment. This means that assuring the safety of fresh produce, including lettuce and leafy greens, depends on preventing contamination throughout the produce supply chain, from farm to fork.  This can prove to be a challenging task given that most fresh produce is grown in an outdoor environment that is open to potential soil, air, water and windborne environmental contaminants, occasionally including human pathogens. Therefore, a key premise regarding produce safety is assuring that agricultural inputs like agricultural water and soil amendments are as free of human pathogens as possible and assuring that food contact surfaces that touch fresh produce, like hands and conveyor belts, don't become a means of produce contamination.

Many fresh produce items are often consumed raw without the kill-step of cooking that can eliminate human pathogens. Commercial or in-home washing of fresh fruits and vegetables before consumption can reduce risk but washing alone cannot eliminate human pathogens that may be present on fresh produce before consumption. This is because human pathogens can get into nooks and crannies of fresh produce where wash water with or without a disinfectant simply cannot reach.

Foodborne illness, also called food poisoning, is a serious national public health problem. Each year it causes an estimated 48 million people to get sick, 128,000 to be hospitalized, and 3,000 to die. The FDA is committed to food safety and protecting consumers from foodborne illness, including those due to E.coli.

For the latest food safety news, and tips on everyday food safety practices to prevent foodborne illness, please see: www.foodsafety.gov.

Recent and Ongoing E. Coli Outbreaks

  • December 2019: Outbreak Investigation of E. coli: Salad Mix
    As of January 15, 2020, the CDC reports that the outbreak appears to be over. Contaminated Fresh Express Sunflower Crisp Chopped salad kits that made people sick in this outbreak are likely no longer available on the market.
  • November 2019: Outbreak Investigation of E. coli: Romaine from Salinas, California
    As of January 15, 2020, the CDC reports that the outbreak appears to be over. Contaminated romaine from the Salinas, CA growing region that made people sick in this outbreak is likely no longer available. Consumers need not avoid romaine lettuce, or any other produce, from the Salinas, CA growing area.
  • July 2019: Outbreak Investigation of E. coli: Ground Bison
    The FDA, along with the CDC, state and local partners in the U.S., and with the support of the Canadian Food Inspection Agency (CFIA), investigated a multistate outbreak of E. coli O121 and E. coli O103 illnesses likely linked to ground bison supplied by Northfork Bison Distributions Inc. of Saint-Leonard, Québec, Canada. On September 13, 2019, CDC announced that the outbreak appears to be over.
  • May 2019: Outbreak Investigation of E. coli: Flour
    The FDA, CDC, and state and local partners, investigated a multistate outbreak of E. coli O26 linked to ADM Milling Co. flour. On July 11, 2019, CDC announced that the outbreak appears to be over.
  • November 2018: Outbreak Investigation of E. coli: Romaine
    As of January 9, 2019, the CDC reports that the outbreak appears to be over. Contaminated romaine that made people sick in this outbreak should no longer be available on the market. On February 13, 2019, FDA released an overview of the investigation approach and factors that potentially contributed to the contamination of romaine lettuce with E. coli O157:H7 in this outbreak.

FDA Action

FDA investigates outbreaks to control them, so more people do not get sick in the outbreak, and to learn how to prevent similar outbreaks from happening in the future. To stop the spread of outbreaks, the FDA, together with federal, state, and local partners, is increasingly using whole genome sequencing to track down sources of food contamination. Applying this technology to food safety, something pioneered by FDA and the GenomeTrakr network, helps public health investigators identify contaminated foods and figure out how the pathogens entered the food supply.

Most recently, the FDA 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.

See below for other recent FDA actions to ensure the safety of the food supply:

  • FDA Investigated Multistate Outbreak of E. coli O157:H7 Infections Linked to Romaine Lettuce from Yuma Growing Region
  • FDA Ends Investigation of E. coli O157:H7 Outbreak Likely Linked to Leafy Greens
  • Environmental Assessment: Factors Potentially Contributing to the Contamination of Romaine Lettuce Implicated in a Multi-State Outbreak of E. coli O157:H7 
    • Memo of investigation
  • Letter to state agriculture officials and the leafy greens industry.
  • Investigation Summary: Factors Potentially Contributing to the Contamination of Romaine Lettuce Implicated in the Fall 2022 Multi-State Outbreak of E. coli O157:H7
  • Microbiological Surveillance Sampling: FY 20 Romaine Lettuce (Raw Agricultural Commodity)
  • FDA Releases Results of Romaine Lettuce Sampling Assignment in Yuma Growing Region

For Consumers

Consumers who have symptoms of foodborne illness should contact their health care provider to report their symptoms and receive care. To report a complaint or adverse event (illness or serious allergic reaction), you have three choices:

  • Call an FDA Consumer Complaint Coordinator if you wish to speak directly to a person about your problem.
  • Complete an electronic Voluntary MedWatch form online.
  • Complete a paper Voluntary MedWatch form that can be mailed to FDA.

Additional Resources

Educational & Outbreak Information

  • Escherichia coli (E. coli) Background Information
  • Foodborne Illness Videos for Consumers
  • Outbreaks of Foodborne Illness
  • Chart of Foodborne Illness-Causing Organisms in the U.S.
  • CDC E.coli Background
  • CDC E.coli Outbreak Information
  • Using Science to Find the Sources of Foodborne Illness Outbreaks
  • Handling Flour Safely: What You Need to Know

FDA Statements & Voices

  • FDA Voices: Outbreaks Emphasize the Importance of Implementing Produce Safety Standards (Jan. 2020)
  • FDA Statement on the Salinas-linked romaine lettuce E. coli O157:H7 outbreak and status update on investigation (Jan. 2020)
  • FDA Statement on new findings and current status of the romaine lettuce E. coli O157:H7 outbreak investigation (Dec. 2019)
  • Deputy Commissioner Frank Yiannas' speech to the International Association for Food Protection (July 2019)
  • FDA Statement on the current romaine lettuce E.Coli 0157:H7 outbreak investigation (Nov. 2018)
  • FDA Statement on new steps to help produce farmers, processors more effectively comply with food safety requirements (Oct. 2018)
  • FDA Voices: Update on Traceback Related to the E. coli O157:H7 Outbreak Linked to Romaine Lettuce (May 2018)