The Iowa Department of Public Health said 15 Iowans had confirmed or suspected infections from the bacteria. The Nebraska health department said 30 residents there had confirmed or suspected cases. A few hospitalizations have been reported, although most people have recovered at home.
The outbreak began last week, and investigators suspect it was linked to alfalfa sprouts grown by an Omaha company, CW Sprouts. Investigators were trying to determine if the contamination happened at the plant or somewhere else in the supply chain.
The company has voluntarily recalled alfalfa sprouts, onion sprouts and gourmet sprouts, which were sold under the brand name SunSprouts. The products were mostly sold in 4-ounce plastic containers, and they were distributed to grocery stores and restaurants in Nebraska and Iowa. Alfalfa sprouts also were sold in larger packages to restaurants.
Iowa officials have suggested that people avoid all such sprouts until the exact cause of the outbreak has been determined.
Salmonella bacteria can cause serious infections, especially in young children, the elderly or people in frail health. Symptoms can include fever, diarrhea, nausea, vomiting and abdominal pain. In rare cases, the bacteria can cause infections through the blood. People who think they might have the illness are urged to call their doctors.
The outbreak is not believed to be related to a nationwide salmonella scare involving peanut butter.