The E. coli O157:H7 leafy greens outbreak Unknown Source 2 investigation is complete, according to an update posted by the FDA. The outbreak was declared over on December 22, 2020, after sickening at least 40 people in 19 states. Twenty people were hospitalized, and four developed hemolytic uremic syndrome, a type of kidney failure. After the investigation, no recommendation was made to consumers, retailers, or suppliers.
Epidemiologic and traceback investigations indicated that leafy greens were linked to this E. coli O157:H7 outbreak. This outbreak was caused by a strain of E. coli that is genetically related to a strain linked to the fall 2019 E. coli O157:H7 romaine outbreak that sickened at least 167 people in 27 states.
The patient case count by state is: Arizona (2), California (6), Illinois (2), Indiana (1), Kansas (4), Michigan (3), Minnesota (2), Missouri (3), North Dakota (4), Ohio (1), Oregon (1), Pennsylvania (2), Tennessee (2), Texas (1), Utah (1), Virginia (1), Washington (1), Wisconsin (2), and Wyoming (1). Illness onset dates ranged from August 10, 2020 to October 31, 2020.
The FDA completed traceback instigation of multiple types of leafy greens that were identified in interviews with patients. No single ranch was identified as a common source of the leafy greens, but the FDA and state partners conducted on-site investigations on farms of interest, which were not named.
Large scale environmental sampling was conducted. No Shiga toxin-producing E. coli bacteria were found on leafy greens. Environmental sampling was collected on and around ranches of interest to identify factors that could have caused the contamination. Samples of soil, scat or animal droppings, compost, water, and other environmental sources were collected and analyzed at labs.
The analysis confirmed a positive match to the outbreak strain in a sample of cattle feces, which was on a roadside uphill from where leafy greens were grown. This finding is not definitive proof about how the bacteria may have contaminated product during the growing and harvesting season, but it does confirm the presence of a strain of E. coli O157:H7 that causes recurring outbreaks in a narrowly defined growing region.
FDA’s investigational activities into this E. coli O157:H7 leafy greens outbreak Unknown Source 2 have ended. The information is being reviewed and a more detailed report will be released by the government in the “near future.” This report will include recommendations.
If you or a loved one have been diagnosed with an E. coli O157:H7 infection or HUS, please contact our experienced attorneys for help at 1-888-377-8900 or 612-338-0202.
