Roundy’s Supermarkets is voluntarily removing all pre-packaged fresh spinach from its grocery store shelves, according to the Associated Press.

Roundy’s stores include Pick ‘n Save, Copps and the Metro Market in Wisconsin. Roundy’s also is taking the spinach out of the Rainbow stores in Minnesota, even though Minnesota isn’t one of the eight states identified by federal health officials.

Health officials are investigating a multistate E. coli outbreak linked to the spinach. The disease has caused one death in Wisconsin and sickened 49 others in eight states.

Twenty cases of the bacterial disease have been confirmed in Wisconsin. State health officials say in all 20 cases, the same strand of E. coli is involved, indicating the source is the same and likely from prewashed, bagged spinach.