Supermarkets around the country have begun pulling packaged spinach from store shelves due to a multistate E. coli outbreak. Ten states are reporting a total of at least 58 cases of E. coli nationwide.

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

The Centers for Disease Control and Prevention and Wisconsin health officials alerted the FDA about the outbreak at midweek. Preliminary analysis suggested the same strain is responsible for the outbreak in all nine states.

Officials believes the spinach may have been grown in California, and federal and state health officials were there trying to pinpoint the source of the contamination.