Federal officials today confirmed another E. coli outbreak that they had previously not revealed to the public. Specific details were not available from the CDC or the FDA, but at least four states have been reported with confirmed patients.

The most likely source of the E. coli O157:H7, reported by 9 of 11 sick people who ate at fast food locations, was lettuce on Subway sandwiches, according to a source close to the investigation. Neither the FDA nor the CDC would confirm that Subway products are involved.

“This is an ongoing investigation into an outbreak that was identified in December,” Food Safety News learned from Peter Cassell, a press officer for the Food and Drug Administration. 

“Upon detection, the outbreak had already ended. In an abundance of caution and to try to inform future prevention, we are working to see if we can identify the source. Per CDC and FDA policy, since there were no specific, clear and actionable steps for consumers to take to protect themselves from contaminated food associated with this outbreak, there was and is no current public health advisory.

“Should our investigation conclusively identify a source and/or contributing factors that could inform future prevention, we are committed to publicly communicating these insights.”

The CDC also provided Food Safety News with confirmation of the previously undisclosed outbreak. An official comment from the agency did not include any specific details except that patients were confirmed in four states.

“In early December 2019, CDC, along with the U.S. Food and Drug Administration and four states, began investigating a multistate outbreak of E. Coli O157 infections,” according to a press officer from the Centers for Disease Control and Prevention.

“No new illnesses have been reported since CDC initially identified this cluster, and the outbreak is over. CDC is continuing to work with FDA to identify the source of the outbreak.”

The four states are Nevada, Maine, Vermont and New Hampshire, according to a source close to the investigation.

On Halloween, Food Safety News learned of another E. coli O157:H7 outbreak that the two federal agencies had not revealed to the public. It ended in September and involved romaine lettuce. 

Spokespeople from FDA and CDC told Food Safety News that because they believed all of the implicated romaine had passed expiration dates by the time the outbreak was discovered, agency officials did not think the public needed to know.

About E. coli infections
Anyone who has eaten at Subway restaurants and developed symptoms of E. coli infection should seek medical attention and tell their doctor about their possible exposure to the bacteria. Specific tests are required to diagnose the infections, which can mimic other illnesses.

The symptoms of E. coli infections vary for each person but often include severe stomach cramps and diarrhea, which is often bloody. Some patients may also have a fever. Most patients recover within five to seven days. Others can develop severe or life-threatening symptoms and complications, according to the Centers for Disease Control and Prevention (CDC).

About 5 to 10 percent of those diagnosed with E. coli infections develop a potentially life-threatening kidney failure complication, known as a hemolytic uremic syndrome (HUS). Symptoms of HUS include fever, abdominal pain, feeling very tired, decreased frequency of urination, small unexplained bruises or bleeding, and pallor.

Many people with HUS recover within a few weeks, but some suffer permanent injuries or death. This condition can occur among people of any age but is most common in children younger than five years old because of their immature immune systems, older adults because of deteriorating immune systems, and people with compromised immune systems such as cancer patients.

People who experience HUS symptoms should immediately seek emergency medical care. People with HUS will likely be hospitalized because the condition can cause other serious and ongoing problems such as hypertension, chronic kidney disease, brain damage, and neurologic problems.

(To sign up for a free subscription to Food Safety News, click here.)