Largest Shiga toxin E. coli outbreak since 2006 widens

Fourteen more people have become ill from Escherichia coli linked to romaine lettuce grown in the Yuma Arizona region, bringing the total number of those impacted by this outbreak to 98 people in 22 states, according to the FDA and CDC.

Officials said the latest cases are from Mississippi, Tennessee and Wisconsin. They added that everyone needs to take precautions as those sickened throughout the outbreak range in age from the very young to very old, with a median age of 31 years.

“This is a serious E. coli,” Matthew Wise, PhD, MPH, deputy branch chief for outbreak response at the CDC, said in a conference call with reporters. “Everybody should be concerned, and everybody should be avoiding romaine [lettuce]. This is not a time to be tailoring the message to risk groups. It’s about E. coli and anyone who consumes it can get really sick.”

Of the first 87 patients who became ill, 46 have been hospitalized, which officials conceded is a higher than normal hospitalization rate for E. coli. Further, 10 patients received a diagnosis of a type of kidney failure known as hemolytic uremic syndrome.

“The Shiga toxin strain in this outbreak is STX-2 only producing E. coli ... one that tends to cause more severe illness based on the toxin profile it produces,” Wise said.

Officials said romaine lettuce products from a farm in Yuma harvested between March 5 and March 16 of this year are the source of the contaminated lettuce that made eight inmates at a prison in Alaska ill. However, there are more than two dozen other farms under investigation as possible parts of this latest outbreak.

“We have not determined where in the supply chain the contamination occurred. We are continuing to examine all possibilities, including that contamination may have occurred along the growing, harvesting, packaging and distribution chain before reaching the Alaskan correctional facility,” Stic Harris, DVM, MPH, director of the FDA’s Coordinated Outbreak Response and Evaluation Network, said during the call. “We are investigating dozens of other sources of the chopped romaine lettuce.”

Currently, there is no link between this strain and the one in Canada from December 2017, which sickened at least 17 people, officials said. Concerns regarding the Arizona-based romaine lettuce outbreak first surfaced on April 10, when a few states, the CDC, the FDA and the U.S. Department of Agriculture’s Food Safety and Inspection Service announced a multistate outbreak of Shiga toxin-producing E. coli O157:H7 infections.

The CDC and FDA said more cases from the romaine lettuce outbreak are expected, due to the lag time between symptoms and the time that they are confirmed as part of the outbreak. The agencies also stressed that people avoid eating romaine lettuce grown in the Yuma, Arizona area. There is no evidence that any other type of lettuce, as well as romaine lettuce grown outside the Yuma Arizona region, is causing the outbreak. If there is any uncertainty as to food products’ origin or type, consumers should throw it out.

Officials added the Yuma Arizona E. coli outbreak is the largest Shiga toxin multi-state E. coli outbreak since 2006, when a similar outbreak linked to spinach was responsible for making more than 200 people ill. – by Janel Miller

Disclosure: Wise works for the CDC, Harris works for the FDA.