WASHINGTON – An outbreak of E. coli in eight states has left at least one person dead and 50 others sick, federal health officials said Thursday in warning consumers not to eat bagged fresh spinach.

The death occurred in Wisconsin, where 20 others were also sickened, said Dr. David Acheson of the Food and Drug Administration’s Center for Food Safety and Applied Nutrition. The outbreak has sickened others – eight of them seriously – in Connecticut, Idaho, Indiana, Michigan, New Mexico, Oregon and Utah.

FDA officials do not know the source of the outbreak other than it appears to be linked to bagged spinach. “We’re advising people not to eat it,” Acheson said.

The outbreak has affected a mix of ages, but most of the cases have involved women, Acheson said.

The Centers for Disease Control and Prevention and Wisconsin health officials alerted the FDA about the outbreak Wednesday. Preliminary analysis suggests the same bug is responsible for the outbreak in all eight states.

E. coli causes diarrhea, often with bloody stools. Most healthy adults can recover completely within a week, although some people – including the very young and old – can develop a form of kidney failure that often leads to death.

Anyone who has gotten sick after eating raw packaged spinach should contact a doctor, officials said.

Other bagged vegetables, including pre-packaged salads, apparently are not affected. In general, however, washing all bagged vegetables is recommended.

E. coli lives in the intestines of cattle and other animals and typically is linked to contamination by fecal material. It causes an estimated 73,000 cases of infection, including 61 deaths, each year in the United States, according to the federal Centers for Disease Control and Prevention.

Sources of the bacterium include uncooked produce, raw milk, unpasteurized juice, contaminated water and meat, especially undercooked or raw hamburger, the agency says on its Web site.