Outbreak Investigation Updates by Date
Posted on January 15, 2020 at 3:00 PM ET
This outbreak appears to be over. E. coli is an important cause of illness in the United States. Find more information about steps you can take to reduce your risk of infection on the E. coli and Food Safety web page.
CDC, public health and regulatory officials in several states, and FDA are investigating a multistate outbreak of Shiga toxin-producing E. coli O157:H7 infections. This investigation includes illnesses in Canada recently reported by the Public Health Agency of Canadaexternal icon. This outbreak is caused by a different strain of E. coli O157:H7 than the current outbreak linked to romaine lettuce from the Salinas, California, growing region.
Public health investigators are using the PulseNet system to identify illnesses that may be part of this outbreak. PulseNet is the national subtyping network of public health and food regulatory agency laboratories coordinated by CDC. DNA fingerprinting is performed on E. coli bacteria isolated from ill people by using a standardized laboratory and data analysis method called whole genome sequencing (WGS). CDC PulseNet manages a national database of these sequences that are used to identify possible outbreaks. WGS gives investigators detailed information about the bacteria causing illness. In this investigation, WGS showed that bacteria isolated from ill people in the United States and Canada are closely related genetically. This means that people in this outbreak are more likely to share a common source of infection.
As of December 9, 2019, a total of eight people infected with the outbreak strain of E. coli O157:H7 have been reported from three states. A list of the states and the number of cases in each can be found on the Map of Reported Cases page.
Illnesses started on dates ranging from November 5, 2019, to November 15, 2019. Ill people range in age from 21 to 91, with a median age of 32. Among ill people, 63% are female. Three of the eight ill people have been hospitalized, including one person who developed hemolytic uremic syndrome, a type of kidney failure. No deaths have been reported.
Investigation of the Outbreak
Information collected to date indicates that Fresh Express Sunflower Crisp chopped salad kits are a likely source of this outbreak.
State and local public health officials are interviewing ill people to determine what they ate and other exposures in the week before their illness started. Of seven ill people with information available, all seven (100%) reported eating any leafy green in the week before their illness started. Six ill people reported eating or maybe eating a Fresh Express Sunflower Crisp chopped salad kit.
The investigation is ongoing to determine which ingredient in the salad was contaminated. Romaine lettuce is one of the ingredients in the salad kit, but we do not know yet if this outbreak is related to a current outbreak linked to romaine lettuce from the Salinas, California, growing region. Preliminary information indicates that romaine lettuce in the salad kits eaten by some of the sick people likely came from the Salinas growing region. CDC is concerned that these kits may still be in some homes. If you have any of these salad kits in your home, throw them away.
CDC will provide more information as it becomes available.