A total of 13 people infected with the outbreak strain of Salmonella Muenchen have been reported from four states. The number of ill people identified in each state is as follows: Kansas (5), Missouri (3), Oklahoma (3), and Pennsylvania (2).

Illnesses started on dates ranging from December 1, 2015 to January 21, 2016. Ill people range in age from 18 years to 73, with a median age of 51. Ninety-two percent of ill people are female. Among 13 ill people with available information, 5 reported being hospitalized, and no deaths have been reported.

Collaborative investigative efforts of state, local, and federal public health and regulatory officials indicate that alfalfa sprouts produced by Sweetwater Farms of Inman, Kansas are a likely source of this outbreak.

In interviews, ill people answered questions about foods eaten and other exposures in the week before they became ill. Of the 12 ill people who were interviewed, 10 (83%) reported eating or possibly eating sprouts in the week before illness started. When asked about the type of sprouts eaten, nine (90%) of these ten ill people reported eating alfalfa sprouts. One ill person reported purchasing Sweetwater Farms brand alfalfa sprouts from a grocery store.

State and local health and regulatory officials performed traceback investigations from five different restaurant locations where ill people ate sprouts. These investigations indicated that Sweetwater Farms supplied alfalfa sprouts to all five locations.

Laboratory testing isolated Salmonella from samples of irrigation water and alfalfa sprouts collected during a recent inspection at Sweetwater Farms. Further testing is ongoing to determine the type and DNA fingerprint of Salmonella isolated in these samples.