Federal officials announced a multistate recall of shredded romaine lettuce sold to wholesalers, restaurants and in "grab and go" packages after least 19 people fell ill from an uncommon strain of E. coli that is not always included in laboratory tests for infections.
Twelve people have been hospitalized since April 10, 2010, and three people developed kidney failure, the U.S. Centers for Disease Control and Prevention said in a press release.
Freshway Foods of Sidney, Ohio, voluntarily recalled lettuce sold in 23 states under the Freshway and Imperial Sysco brands.
The U.S. Food and Drug Administration announced that consumers should discard the recalled bags with a "best if used by" date of May 12 or earlier. Lettuce with "best if used by" date after May 12 are not included in the recall.
Recalled bags of shredded lettuce were sold to Kroger, Giant Eagle, Ingles Markets and Marsh grocery stores, according to The Associated Press.
States affected by the recall include: Alabama, Connecticut, District of Columbia, Florida, Georgia, Illinois, Indiana, Kansas, Kentucky, Maryland, Massachusetts, Michigan, Missouri, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Virginia, West Virginia and Wisconsin.
Local health officials were alerted by an outbreak of the O145 E. coli among college students at the University of Michigan in Ann Arbor, Ohio State in Columbus and Daemen College in Amherst, N.Y., according to the AP.
Vice president of Freshway Foods Devon Beer told the AP that federal officials have traced the contaminated lettuce to a farm in Yuma, Ariz.
Food safety experts said the O145 strain of E. coli that caused this outbreak is one of six toxic E. coli strains outside of the more common O157 strain, which causes most E. coli related illnesses.
As a result, the O145 strain is not always included in laboratory tests for E. coli.
"Most laboratories may not have the capacity to identify this particular strain," said Philip M. Tierno, director of clinical microbiology and immunology at New York University Langone Medical Center in New York City.
"It very well could be not seen in most labs if a person [with O145] would go into the ER have a stool cultured they may not be able to identify it," he said.
Most E. coli detected in humans is found in the gut, and is harmless. But Tierno said O145, 0157 and five other strains are known to carry some 50 Shiga toxins, which leads to serious illness and death.
Symptoms include severe diarrhea, bloody diarrhea and fever, according to the National Institutes of Health.
Tierno said many labs only test for O157, and would need a general Shiga toxin analysis test to detect the others.
"The first thing you have to figure is -- in this particular case it's romaine lettuce -- consumers should be aware of the brand of romaine lettuce and avoid it," said Tierno. "Unfortunately, there's nothing else consumers can do -- even if the lettuce is washed it may not be sufficient."
As in the 2006 E. coli contamination of bagged spinach, Tierno said people may not be able to wash the pathogen off the leaf -- especially if the source of the E. coli is water contaminated with animal feces.