Another 13 people have been confirmed sick in an outbreak of E. coli O157:H7 infections linked to lettuce on sandwiches from Wendy’s restaurants. Two states have been added to the outbreak.

Half of the 97 outbreak patients have been so sick that they had to be admitted to hospitals. Of the 43 hospitalized people, 10 have developed a kind of kidney failure known as hemolytic uremic syndrome (HUS), according to the Centers for Disease Control and Prevention.

Among the 67 people with detailed food histories, 81 percent reported eating at Wendy’s restaurants. Of 54 people with further information about what they ate at Wendy’s, 37 reported eating romaine lettuce served on burgers and other sandwiches.

“The true number of sick people in this outbreak is likely higher than the number reported, and the outbreak may not be limited to the states with known illnesses,” according to the CDC outbreak update. “This is because some of the recent illnesses have not yet been reported to PulseNet as it usually takes 3 to 4 weeks to determine if a sick person is part of an outbreak. In addition, some people recover without medical care and are not tested for E. coli.”

The sick people reported eating at various Wendy’s restaurants in Michigan, Ohio, Indiana and Pennsylvania. Sick people confirmed so far are from those four states plus Kentucky and New York.

Wendy’s stopped serving lettuce on its sandwiches in the outbreak region earlier this month. The lettuce in its other products is a different kind than that used for sandwiches, according to a statement from the company.

Illnesses started on dates ranging from July 26 to Aug. 15. Sick people range in age from 3 to 94 years, with a median age of 22 years. More than half, 55 percent, are male.

“Investigators are working to confirm whether romaine lettuce is the source of this outbreak, and whether romaine lettuce used in Wendy’s sandwiches was served or sold at other businesses,” according to the CDC.

“CDC is not advising people to avoid eating at Wendy’s restaurants or to stop eating romaine lettuce.”

About E. coli infections

Anyone who has 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.

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