The Centers for Disease Control and Prevention (CDC) said Salmonella Reading and Salmonella Abony infections have been reported from nine states and five people have been hospitalized.
The US Food and Drug Administration (FDA) said alfalfa sprouts supplied by Sprouts Extraordinaire of Denver, Colorado are the likely source of the outbreak.
Since 1996, there have been at least 30 reported outbreaks of foodborne illness associated with different types of raw and lightly cooked sprouts.
Sprouts Extraordinaire recall
Sprouts Extraordinaire has recalled products due to possible contamination.
The firm recalled 5lb boxes of alfalfa sprouts harvested on July 4 to 26. They are labeled “Living Alfalfa Sprouts” and were not sold directly to consumers.
CDC recommended that consumers do not eat and restaurants and other retailers do not sell or serve recalled alfalfa sprouts supplied by Sprouts Extraordinaire.
Of the ill people, 24 were infected with Salmonella Reading, one with Salmonella Abony, and five were infected with both.
Illness dates range from May 21 to July 20. Ill people range in age from less than one to 72 and 53% are female.
Illnesses after July 12 might not yet be reported as it takes an average of two to four weeks between when a person becomes ill and when the illness is reported.
Alfalfa sprouts in restaurants
Of 27 ill people interviewed, 17 (63%) reported eating or possibly eating alfalfa sprouts in the week before illness started. They reported eating raw alfalfa sprouts on sandwiches from several different restaurants.
CDC said this is significantly higher than results from a 2006 survey of healthy people, in which 3% reported eating sprouts on a sandwich in the week before they were interviewed.
A traceback investigation from five restaurants where ill people reported eating alfalfa sprouts indicated that Sprouts Extraordinaire supplied to all five locations.
FDA said it will work with downstream companies to ensure recalled product is removed from the market.