(UPDATED, Dec. 6) The number of people sickened in an illness outbreak caused by E. coli O157:H7 linked to romaine lettuce from Salinas, Calif. continues to grow, while traceback investigators are focusing on three farms in the region.
In a Dec. 4 update, the Centers for Disease Control said the number of cases in the outbreak totaled 102 individuals in 23 states. The CDC said the latest date that one of patients reported becoming ill was Nov. 18. Wisconsin reported 31 outbreak cases, the most of any state.
The total of 102 reported sick Dec. 4 was a 52% increase from the previous update on Nov. 25, when 67 people in 19 states were infected with the outbreak strain.
The CDC said Dec. 4 that a total of 58 hospitalizations have been reported, and ten people have developed hemolytic uremic syndrome, a type of kidney failure. No deaths have been reported.
Federal health officials continue to advise consumers not to eat romaine lettuce harvested from Salinas, Calif., which includes Santa Cruz, Santa Clara, San Benito, and Monterey counties in California.
“At this time, romaine lettuce that was harvested outside of the Salinas region has not been implicated in this outbreak investigation,” the FDA said in the Dec. 4. “Hydroponically- and greenhouse-grown romaine, which is voluntarily labeled as “indoor grown,” from any region does not appear to be related to the current outbreak. There is no recommendation for consumers to avoid using romaine harvested from these other sources.”
Calling the situation “evolving and fluid,” the FDA reported Dec. 4 that the agency continues to investigate the cause of this outbreak.
“FDA, with the assistance of staff from the California Department of Public Health and the California Department of Food and Agriculture, immediately deployed investigators to three farms in the Salinas area that were identified based on the traceback investigation,” the agency said. The FDA said investigators sampled soil and animal droppings, compost, water, and other potential environmental sources.
“The samples and information collected during the farm investigations are currently being analyzed,” the FDA said.
Investigators are attempting to identify any factors that could have led to contamination, the agency said. State partners also are testing romaine lettuce samples for E. coli that they have collected from stores and from case patients’ homes, the FDA said.
The FDA and state partners are conducting a traceback investigation to determine whether a common supplier or source of contamination can be identified.
“This investigation involves collecting and analyzing potentially hundreds of distribution records to trace the romaine that may have been available at points of exposure reported by ill people to their source,” the agency said. “We are continuing to collect these records.”
Trevor Suslow, vice president of produce safety for the Produce Marketing Association, said in an e-mail Dec. 5 that the FDA and the CDC identified another seasonal spike in illness of the E. coli O157:H7 WGS subtype highly related to 2017 and 2018 late summer-fall outbreaks.
“Environmental samples, taken off-farm, have been reported to be highly related to the earlier and current outbreak,” Suslow said in the e-mail.
”These findings, while early in the overall effort, seem to support the conviction that there is both a level of environmental persistence and a source of this particular isolate being dispersed broadly by mechanisms and routes yet to be clearly identified.”
In a news release, the California Leafy Greens Marketing Agreement said the group hopes to learn information that will help the industry identify how romaine came to be the source of this outbreak.
“The LGMA has already begun the process of thoroughly examining the mandatory food safety practices followed by 90% of the leafy greens grown in the U.S. that are regulated under the LGMA programs in California and Arizona,” the LGMA said.
“We pledge to take every possible action to prevent future outbreaks.” P