Utah is one of eight states experiencing unusually high numbers of E. coli cases, and at least some of the outbreaks appear to be linked to "pre-washed" spinach, according to state health officials and the Food and Drug Administration. Statewide, 10 cases are being investigated so far.

The investigation indicates at least some of the E. coli cases appear to be strongly associated with ready-to-eat packaged spinach. The link is strong enough that FDA officials first said people should cook bagged spinach thoroughly, but later changed their warning to telling consumers not to eat it at all "at this time."

E. coli outbreaks that may be linked to the prepackaged spinach are in Utah, Oregon, Wisconsin, New Mexico, Michigan, Idaho, Indiana and Connecticut.

To avoid E. coli, the FDA said that all bagged spinach must at the very least be thoroughly cooked. The Center for Science in the Public Interest said that, of 225 food-poisoning outbreaks from 1990 to 1998, nearly 20 percent were linked to fresh fruits, vegetables or salads.