Calif. Farm Firm Linked To Tainted Spinach

"We will do whatever is necessary to help protect the health and safety of the public," the statement said.

David Acheson, an FDA food safety official, emphasized last night that no E. coli bacteria has been isolated from any of Natural Selection's products and that recalls could extend beyond Natural Selection Foods. Samples of spinach that several patients still had in their refrigerators are being shipped to FDA labs for testing.

Food safety experts have been recently tracking an increase in the number of food-borne illnesses in fresh produce. Outbreaks in produce have been more frequent than beef and poultry in recent years, according to federal health statistics analyzed by the Center for Science in the Public Interest. From 1998 to 2004, there were 492 outbreaks of food-borne illnesses attributed to produce, including 86 in 2004. In the same period there were 324 outbreaks traced to beef, 402 to poultry and 626 to seafood.

Caroline Smith DeWaal, food safety director for the Center for Science in the Public Interest, said it was not clear what caused the increase in produce problems. "What is clear is that the numbers show they are not going down," she said.

James Gorny, senior vice president for food safety and technology at the United Fresh Produce Association, attributed the increase to several factors, including increased consumption of produce, better detection methods and advances in epidemiology. He said the public is also more aware of problems that could arise from tainted produce.

"We never thought to look at fruits and vegetables before, and now we are," he said.

Gorny said the industry has improved its communication with regulatory agencies and recently issued guidelines for handling melons, tomatoes, lettuce and leafy greens.

"These documents don't just sit on a table," he said. "We really try to get them out to industry."

Tom Stenzel, president and chief executive of the United Fresh Produce Association, said it is working closely with the FDA to determine the source of the current outbreak. "We've got to make sure consumers retain their confidence in the safety of these products," he said yesterday during a news conference at the National Press Club in Washington.

The outbreak prompted questions about how packaged spinach is produced. Gorny said it is sent to a processing facility after harvesting, where it is cooled and triple-washed in chlorinated water, "probably a more vigorous wash cycle than you can ever do in your home." The spinach is then dried, packaged and refrigerated before being shipped to distributors.

Raw, bulk spinach is harvested and packaged but not washed before it is sent to distributors, Gorny said. Stenzel cautioned that produce tainted with E. coli cannot be decontaminated simply by washing. "You can certainly reduce risk by washing the product, but you cannot eliminate the risk," he said.

The only way to eliminate the risk is to cook the product to at least 160 degrees, but health officials advised against that, saying preparing contaminated food could spread the bacteria.

Staff writers David Brown and Dina ElBoghdady contributed to the report.