FRIDAY, Dec. 8, 2006 (HealthDay News) -- U.S. health officials are still trying to determine the source of the E. coli outbreak linked to Taco Bell restaurants that has now sickened scores of people in at least six states.
And they predicted that the number of victims will rise in coming days, because symptoms of E. coli O157 infection sometimes don't appear for up to a week after eating contaminated food.
"Illnesses are still occurring," Dr. Christopher Braden, an epidemiologist with the U.S. Centers for Disease Control and Prevention, told a news teleconference Friday afternoon. "The outbreak is still going on."
Reports of infections have spread beyond the initial outbreaks in New Jersey, New York and Pennsylvania, to Delaware, South Carolina and Utah, CDC health officials said.
As of Friday afternoon, the CDC reported 63 confirmed cases of E. coli infection in six states.
New Jersey has 28 confirmed cases; New York has 22; Pennsylvania has 9, Delaware has 2, and South Carolina and Utah have one each, according to the CDC list.
But, state health department officials report that New Jersey also has 55 potential cases, and New York has 220, including 177 on Long Island, according to Bloomberg News.
Of the confirmed cases on the CDC list, 79 percent of the victims required hospitalization and 11 percent have developed a form of kidney failure called hemolytic-uremic syndrome, the agency said.
Green onions have been considered a possible source of the infections but that still hasn't been confirmed, Braden added.
Besides testing vegetables, the CDC and the U.S. Food and Drug Administration are examining cheese used at Taco Bell restaurants, said Dr. David Acheson, chief medical officer at the FDA's Center for Food Safety and Applied Nutrition.
"There is no data to implicate or rule out any food item," Acheson added during the teleconference, stressing that green onions haven't been confirmed as the source of the outbreak. The CDC and FDA are testing food samples from Taco Bell restaurants and from food distributors. Such samples are routinely set aside in case health problems arise, Acheson said.
Several laboratories are also testing food samples from Taco Bell restaurants, according to the CDC. Some of those preliminary tests have indicated the possible presence of E. coli O157 in samples of green onions, but the tests have not been confirmed.
Those tests have led officials to focus on Boskovich Farms in Oxnard, Calif., which grows the green onions for the supplier of Taco Bell, The New York Times reported Friday.
Earlier this week, Taco Bell removed the green onions, also called scallions, from its 5,800 restaurants nationwide. "We're focused on working with the authorities to find the root cause," said Rob Poetsch, a spokesman for Yum! Foods, which owns Taco Bell.
However, it still isn't clear if the green onions could have been contaminated at Boskovich Farms; at a Ready Pac Produce plant in Florence, N.J., where they were processed; or at a warehouse of McLane Foodservice in Burlington Township, N.J., which distributed them to Taco Bell outlets in eight northeastern states.
Laboratory testing found three samples of green onions that appeared to have a harsh strain of E. coli.
However, FDA spokesman Michael L. Herndon said, "All we have been given is presumptive evidence only from a contract lab whose results we can't confirm."
Federal authorities said Thursday that there were no plans to issue general warnings about green onions, the Associated Press reported.
Ready Pac is the sole supplier of green onions to Taco Bell. This is the second E. coli scare to hit Ready Pac in the past four months.
In September, spinach with the Ready Pac label was among the brands pulled from the shelves after federal authorities traced a nationwide E. coli outbreak to a Natural Selections processing plant that bags Ready Pac fresh spinach, the AP said. That outbreak sickened 199 people in 26 states and Canada and left three dead.
Also in September, an outbreak of salmonella was traced to tomatoes served in restaurants. The outbreak sickened 183 people in 21 states, as well as two people in Canada.
Meanwhile, the first lawsuit stemming from the latest E. coli outbreak has been filed, by the family of an 11-year-old Long Island boy who got sick after eating at a Long Island Taco Bell. The suit against Taco Bell seeks an undisclosed amount in damages.
One expert thinks the recent spate of food-borne problems is a sign of new dangers in the U.S. food production and distribution system, which has become increasingly mechanized.
"This [the latest E. coli outbreak] is one of a series of outbreaks, which represent a change in the pattern of food-borne outbreaks," said Dr. Pascal James Imperato, chairman of the Department of Preventive Medicine and Community Health and director of the Master of Public Health Program at SUNY Downstate Medical Center in Brooklyn, N.Y.
Previously, E. coli contamination occurred at the place where food was served as opposed to the source of growing and production, Imperato said. "This outbreak and the spinach outbreak are really a newer development. We are now seeing contamination at the source of production," said Imperato, a former New York City health commissioner.
Since growing and distributing vegetables has become an "agribusiness," with fewer but larger growers, processors and distributors, there's more chance of contamination, Imperato added. Contamination can occur from irrigation, which can spread E. coli from neighboring animal grazing lots, and during the packaging in large plants. And that packaging increasingly relies on plastic bags, which create an ideal environment for bacteria such as E. colito grow, he explained.
Imperato said he thought the only solution to the problem is increased government oversight and regulation.
Currently, the FDA is responsible for monitoring produce and seafood, while the U.S. Department of Agriculture has oversight for meat and poultry. But, while the FDA has published sanitary standards for produce farmers, the agency has no regulatory authority to enforce those standards. Also, the FDA has few inspectors to even observe the level of voluntary compliance to those standards, Imperato said.
"It's going to require more rigorous oversight and the implantation and adherence to standards from the time the crop is grown in the field through the entire processing of the product and its distribution," he added.
Acheson agreed that new farming and distribution practices have increased the risk for contamination. Given the latest outbreak and the spinach problem in September, "it's fairly clear that something needs to changed," he said.
New regulation may be a part of the solution, Acheson said. But, he added, more may have to be done, including changing some farming and processing practices.
E. coli O157:H7 is one of hundreds of strains of the bacterium Escherichia coli. Although most strains are harmless, this strain produces a powerful toxin that can cause severe illness, such as bloody diarrhea and abdominal cramps. The symptoms usually clear up within five to 10 days, according to the CDC.
For more on the latest E. coli outbreak, visit the U.S. Centers for Disease Control and Prevention.