A multi-state food poisoning outbreak linked to alfalfa sprouts has spread across 15 states, federal health officials said.

State authorities initially reported more than three dozen cases in Minnesota and Wisconsin earlier this week. On Friday, the U.S. Centers for Disease Control and Prevention confirmed 55 cases nationwide, including four hospitalizations.

Additional cases were reported in Florida, Indiana, Iowa, Kansas, Michigan, New Hampshire, New York, Pennsylvania, North Carolina, South Carolina, North Dakota, South Dakota, and Washington.

Of 34 sick individuals interviewed, 26 reported eating alfalfa sprouts, according to the U.S. Food and Drug Administration.

While most food poisoning outbreaks stem from a single germ, this instance involves people infected with salmonella and different strains of E. coli.

Shiga toxin-producing E. coli — or STEC — causes stomach cramps and bloody diarrhea, which can lead to severe acute kidney failure. Salmonella poisoning causes diarrhea, fever, severe vomiting, dehydration, and stomach cramps.

Investigators traced cases to alfalfa sprouts from Minnesota grower Everything Sprouts, sold to restaurants and grocery stores under the Calco and Everything Sprouts labels. The FDA said the company has not issued a recall.

Last year, the FDA sent a warning letter to Everything Sprouts after earlier inspections raised safety concerns, including a leaky roof that dripped water onto bean sprouts and staff smocks.

The Associated Press left messages for Everything Sprouts seeking comment.