ATLANTA -- U.S. health officials said late last week that they are still trying to determine the source of the E. coli outbreak linked to Taco Bell restaurants that has sickened at least 63 people in six states, reported HealthDay News.
And the number of cases is expected to continue to rise in coming days, because symptoms of E. coli O157 infection sometimes do not appear for up to a week after eating contaminated food, the officials said. "Illnesses are still occurring," Dr. Christopher Braden, an epidemiologist with the federal Centers for Disease [image-nocss] Control & Prevention (CDC), said during a news teleconference. "The outbreak is still going on."
Green onions are considered a possible source of the infections, but that hasn't been confirmed, Braden said.
Reports of infections have spread beyond the initial outbreaks in New Jersey, New York's Long Island, and Pennsylvania, to Delaware, South Carolina and Utah, the CDC said.
As of Friday afternoon, the CDC reported 63 confirmed cases of E. coli infection in six states; 79% percent of the people required hospitalization, and 11% have developed a form of kidney failure called hemolytic-uremic syndrome. "There are also a number of people under investigation," Braden said.
Most of the cases remain clustered in New Jersey and on Long Island.
On Thursday, officials said there were 99 probable cases of infection in three states, New York, New Jersey and Pennsylvania.
Besides testing vegetables, the CDC and U.S. Food & Drug Administration (FDA) are examining cheese used at Taco Bell restaurants, said Dr. David Acheson, chief medical officer at the FDA's Center for Food Safety & Applied Nutrition.
"There is no data to implicate or rule out any food item," Acheson said during the teleconference, stressing that green onions have not 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 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 last week, Taco Bell removed the green onions, also called scallions, from its 5,800 restaurants nationwide; however, it still is not 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 spokesperson 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 LLC processing plant that bags Ready Pac spinach, the AP said. That outbreak sickened 199 people in 26 states and left three dead after they ate contaminated spinach.
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.
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," Dr. Pascal James Imperato, chairman of the Department of Preventive Medicine & Community Health and director of the Master of Public Health Program at SUNY Downstate Medical Center in Brooklyn, N.Y., told HealthDay News.
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. He said he thinks the only way to solve the problem is through 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, he 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," Imperato said.
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