Federal health officials told California farmers to improve produce safety in a pointed warning letter last November, nearly a year before the multistate E. coli outbreak linked to spinach.
In fact, the current food-poisoning episode is the 20th since 1995 linked to spinach or lettuce, the Food and Drug Administration said.
Though state and federal officials have traced the current outbreak to a California company's fresh spinach, they haven't pinpointed the source of the bacteria that have killed one person and sickened at least 113 others. A second death was being investigated in the outbreak, which involves 21 states.
The FDA is still warning consumers not to eat fresh spinach.
The regulatory agency does not consider the contamination deliberate.
"There is always a question in the back of our mind whether it may have been a deliberate attack on the food supply. Currently, there is nothing in the epidemiology to consider this deliberate," said Dr. David Acheson of the FDA's Center for Food Safety and Applied Nutrition.
That leaves a broad range of other possible sources, including contaminated irrigation water that's been a problem in California's Salinas Valley. The area on California's central coast produces much of the U.S. spinach crop.
19 other food-poisoning outbreaks
There have been 19 other food-poisoning outbreaks since 1995 linked to lettuce and spinach, according to the FDA. At least eight were traced to produce grown in the Salinas Valley. The outbreaks involved more than 400 cases of sickness and two deaths.
In 2004 and again in 2005, the FDA's top food safety official warned California farmers they needed to do more to increase the safety of the fresh leafy greens they grow.
"In light of continuing outbreaks, it is clear that more needs to be done," the FDA's Robert Brackett wrote in a Nov. 4, 2005, letter.
Suggested actions included discarding any produce that comes into contact with floodwaters. Rivers and creeks in the Salinas watershed are known to be periodically contaminated with E. coli, Brackett said.
Meanwhile, the FBI is monitoring the situation, said spokesman Rich Kolko. He called it a routine and precautionary measure, not an indication of suspicious activity.
FDA spokeswoman Susan Bro dismissed a claim by Natural Selection Foods LLC, the company linked to the outbreak, that its organic spinach products had been cleared of suspicion.
"The FDA has not cleared any products from the list and continues to recommend consumers avoid eating fresh spinach products," she said.
The brands include the company's own labels and those of other companies that had contracts with Natural Selection to produce or package its spinach.
Salinas-based River Ranch Fresh Foods recalled spring salad mixes containing spinach sold under the labels Hy-Vee, Fresh N' Easy and Farmers Market, FDA officials said. All contain spinach purchased from Natural Selection.
FDA examines farming practices
The FDA and the California Department of Health Services were reviewing irrigation methods, harvest conditions and other practices at farms possibly involved. Test results on samples from produce packing plants are due in a week or more, Acheson said. FDA inspectors were to visit fields in California later Monday.
"Obviously, it hasn't been perfected to get all the bugs out. But you don't have people fighting back out here. They're just saying, 'Help us, we want to get to the bottom of this,'" Farr said.
The spinach could have been contaminated in the field or during processing. About 74 percent of the fresh-market spinach grown in the U.S. comes from California, according to the California Farm Bureau Federation.
E. coli cases linked to the tainted spinach have been reported in 21 states, with Wisconsin reporting the most cases, including the death of a 77-year-old woman. A death in Ohio was being investigated.
On Monday, Illinois and Nebraska joined the list of states with confirmed cases. Those states are: California, Connecticut, Idaho, Indiana, Kentucky, Maine, Michigan, Minnesota, New Mexico, Nevada, New York, Ohio, Oregon, Pennsylvania, Utah, Virginia, Washington and Wyoming, according to the Centers for Disease Control and Prevention.
Women accounted for 75 percent of the cases, since they probably eat more spinach, Acheson said. Sixty people have been hospitalized in the outbreak.
