Following the Trail of Infection

Dec. 12, 2006— -- The exact cause of the latest outbreak in a four-month saga of E. coli infections remains a mystery. The microbe, which has sickened more than 200 and killed at least three, forces Americans to continue to question the safety of their food.

But while health officials still work to determine who else may be at risk from E. coli, a letter issued to California farmers more than a year ago suggests the industry had ample warning of the bacterial menace.

November 4, 2005

Federal health officials issue a pointed warning letter to California farmers, urging them to improve produce safety. The letter highlights E. coli as a major concern:

"In view of continuing outbreaks associated with fresh and fresh-cut lettuce and other leafy greens, particularly from California, we are issuing this second letter to reiterate our concerns and to strongly encourage firms in your industry to review their current operations in light of the agency's guidance for minimizing microbial food-safety hazards in fresh fruits and vegetables, as well as other available information regarding the reduction or elimination of pathogens on fresh produce."

August 31, 2006

An elderly Nebraska woman dies from what is later determined to be an E. coli infection. The woman, who was in her 80s, ate spinach contaminated with the same strain of E. coli that would later be implicated in sickening hundreds of other people around the country. Her death would be confirmed as resulting from E. coli poisoning on October 6, 2006.

September 14

Another death, a Wisconsin woman, is the first to be linked to the tainted spinach.

September 15

Natural Selection Foods, the nation's largest grower of organic produce, voluntarily recalls fresh spinach products sold in the United States, Mexico and Canada after the U.S. government said they could be linked to a deadly and worsening E. coli outbreak.

September 17

The number of people sickened by an E. coli outbreak traced to tainted spinach rises to 109. Federal officials announce that more brands recall their products in hopes of stemming the infections.

September 20

The E. coli outbreak spreads to two more states. Meanwhile, investigators report finding contaminated spinach in the refrigerator of one victim.

By this time, the outbreak has sickened at least 146 people in 23 states, according to the Centers for Disease Control and Prevention. Seventy-six have been hospitalized, some with kidney failure.

The outbreak also takes its third life. Two-year-old Kyle Allgood of Idaho dies, and two weeks later his death is confirmed as stemming from E. coli-tainted spinach.

September 24

A second bag of spinach contaminated with toxic E.coli bacteria is found in Utah, and regulators hope it offers clues about the outbreak. One hundred and seventy three people are confirmed to have fallen sick so far.

October 5

Agents from the FBI and the Food and Drug Administration launch a criminal investigation into two Salinas Valley produce companies involved in the contaminated spinach outbreak. Investigators hope to determine whether the companies violated food-safety and environmental laws.

October 6

E. coli fears spread to the meat industry as an Iowa-based company recalls more than 5,000 pounds of ground beef after tests detected a harmful strain of the E. coli bacteria. Though no illnesses were reported to be caused by the beef subject to the recall, the meat is suspected of having the same E. coli strain responsible for three deaths in the recent outbreak of contaminated spinach.

October 8

Less than a week after the FDA lifts its warning on fresh spinach grown in California's Salinas Valley, a popular brand of lettuce grown there is recalled Sunday over concerns about E. coli contamination. Though the lettuce does not appear to have caused any illnesses, the scare comes amid other federal warnings that some brands of spinach and bottled carrot juice could also lead to E. coli contamination and cause grave health risks -- including paralysis, respiratory failure and death.

October 12

Investigators find the same strain of deadly bacteria that sickened dozens of people nationwide at a cattle ranch in California's Salinas Valley within a mile of spinach fields.

October 24

A Connecticut company recalls about 1,680 pounds of ground beef products on fears they could be contaminated with E. coli. Once again, no illnesses are linked to the beef subject to the recall.

December 4

A new E. Coli outbreak, this time linked to Taco Bell restaurants, begins in the Northeast. Taco Bell closes four restaurants in New York as a precautionary measure after a suspected E. coli outbreak at one of its New Jersey outlets sickens nearly a dozen people.

December 5

Yum Brands Inc., the parent company of Taco Bell, says a strain of E. coli suspected to have sickened a number of people in the Northeast is no longer in any of its Taco Bell restaurants. The company maintains that there is "no immediate threat" to consumers but adds it is continuing to work with health officials.

December 6

Taco Bell orders scallions removed from its 5,800 U.S. restaurants after tests by an independent lab found three samples of green onions appearing to have a dangerous strain of the bacteria.

December 7

An 11-year-old boy's family files suit against Taco Bell. The family claims negligence by the restaurant chain caused the child to fall ill to E. coli amid an outbreak that has sickened nearly four dozen others. The lawsuit is believed to be the first from the outbreak that has been linked to Taco Bell restaurants in three northeastern states.

Meanwhile, state and federal investigators continue to scrutinize the nonmeat ingredients in the chain's restaurants. So far, 48 people in three states have been sickened by the outbreak.

December 8

Shares of Taco Bell parent Yum Brands Inc. dip more than 2.2 percent on Friday after an analyst downgrades the stock and raises concerns that the E. coli outbreak could have a significant impact on sales.

December 9

Taco Bell says its restaurants are free of E. coli, now that it no longer plans to use green onions. The restaurant chain also calls for an industry review of the produce supply system in the United States.

In eastern Iowa, at least 19 people become sick with suspected cases of E. coli after eating at Taco John's, a fast-food restaurant unrelated to Taco Bell. Health officials say that while the cases suggest E. coli contamination, the finding has yet to be confirmed. Fourteen of the people who become sick have been hospitalized.

December 10

Taco Bell announces that tests have ruled out every ingredient except for scallions as a possible source of a harsh strain of E. coli that by now has sickened more than 60 people in the Northeast.

December 11

White onions join green onions as possible culprits in the E. coli infections. By this time, the CDC has confirmed 61 cases in five states, mostly in New Jersey, New York, Pennsylvania and Delaware, plus one in South Carolina.

December 12

The exact cause behind the Taco Bell E. coli outbreak is still unknown, and health officials have switched their focus to white onions as a possible source.