The Centers for Disease Control and Prevention (CDC) announced two E. coli outbreaks yesterday saying the food source has not yet been confirmed but that the genetic fingerprints of the E. coli O157:H7 cultured from those sickened matches the fingerprints associated with E. coli outbreaks linked to romaine lettuce from Yuma, AZ in 2018 and romaine lettuce from Salinas, CA in 2019. Together the new outbreaks have sickened a total of 44 people. One person has died.

How Were These Outbreaks Discovered?

When an illness is confirmed as an E. coli infection, health officials use Whole Genome Sequencing (WGS) to identify the genetic fingerprint of the strain. They then upload these fingerprints to PulseNet, a national subtyping database coordinated by the CDC. When matching fingerprints appear, it means that people likely shared a common source of infection and an outbreak has occurred.

Using PulseNet, health officials identified two groups of matching E. coli O157:H7 fingerprints, two outbreaks. Then, state and local health departments contacted the people sickened to get food histories of what they ate in the days and weeks before they became ill. Although health officials say they don’t yet know the food source,  here’s what they know so far.

E. coli Outbreak Unknown Source 1

Illnesses in this outbreak sickened people ranging in age from 2 to 75 years old. They reported the onset of illness on dates ranging from June 6, 2020, to October 5, 2020.  Twenty-one illnesses were reported from eight states: CA (7), FL, (1) IL(1), MI (2), NJ (1), OH (7), UT(1) and WI (1).

E. coli Lawyer - CDC Map of E. coli outbreak Unknown Source 1


Local health officials have gathered information for 16 of the people sickened. Eight of them were so sick they were hospitalized including one person who developed hemolytic uremic syndrome (HUS) a form of kidney failure associated with E. coli infections. One person in Michigan died.

There is a restaurant associated with a cluster of illnesses (defined as two or more people from different households) but health officials have not released the name of the establishment.

The fingerprint of the E. coli O157:H7 strain associated with this outbreak is the same one linked to the 2018  outbreak linked to romaine lettuce grown in Yuma, AZ. In that outbreak, 210 people were sickened, 96 were hospitalized, 27 developed HUS and five people died.

E. coli Outbreak Unknown Source 2

Illnesses in this outbreak sickened people ranging in age from 5 to 81 years old. They reported the onset of illness on dates ranging from August 17, 2020, to October 8, 2020. The 23 illnesses were reported from the following 12 states: CA (2), Il (1), KS(4), MI (2), MO (2), ND (4), OH (1), PA (2), TN (1), UT (1), WA (1) and WI (2).

E. coli Lawyer -CDC Map of E. coli Outbreak Unknown Source 2

Health officials have gathered information for 15 of the people sickened. Ten of them have been hospitalized, two with HUS.

The fingerprint of the E. coli O157:H7 strain associated with this outbreak matches the one linked to three outbreaks that occurred in 2019, 2018 and 2017 linked to romaine lettuce grown in Salinas, California.

During interviews with health officials, the people sickened in this outbreak said they had eaten various types of leafy greens before they became ill. Specifically, nine people reported eating iceberg lettuce, nine spinach, eight romaine and six mixed bag lettuce.

The U.S. Food and Drug Administration (FDA) is conducting traceback investigations for both outbreaks, inspecting farms and sampling products in an effort to determine the food source.

If you developed an E. coli infection from contaminated restaurant food or food you purchased from a grocery store and would like a free consultation with an experienced E. coli lawyer, please contact the Pritzker Hageman E. coli Legal Team. We have represented clients in every major E. coli outbreak in the U.S.  You can reach us by calling 1-888-377-8900, sending a text to 612-261-0856, or by completing the form below. The consultation is free and there is no obligation.