As of 11:00 PM EDT on June 2, 2010, a total of 35 individuals infected with a matching strain of Salmonella Newport have been reported from 11 states since March 1, 2010. The number of ill people identified in each state with this strain is as follows: AZ (2), CA (17), CO (1), ID (5), IL (1), MO (1), NM (1), NV (2), OR (2), PA (1), and WI (2). Among those for whom information is available about when symptoms started, illnesses began between March 1, 2010 and May 16, 2010. Case-patients range in age from <1 to 75 years old, and the median age is 36 years. Sixty-six percent of patients are female. Among the 30 patients with available hospitalization information, 7 (23%) were hospitalized. No deaths have been reported.

Collaborative investigative efforts of many local, state, and federal public health, agriculture, and regulatory agencies have linked this outbreak to eating raw alfalfa sprouts. Interviews of case-patients found that most reported eating raw alfalfa sprouts before becoming ill. Some case-patients reported eating sprouts at restaurants; others purchased sprouts at grocery stores. The initial investigation traced the implicated raw alfalfa sprouts to a single sprout processor, JH Caldwell and Sons Inc., in Maywood, California. Investigations are currently ongoing at the sprout processor.