California is the 16th state to join the list, but more than half of the cases are in Illinois.
Most of the people who got sick in Illinois ate sandwiches containing sprouts at Jimmy John's restaurants.
U.S. Food and Drug Administration [FDA] officials say the outbreak may be linked to Tiny Greens organic farm in Urbana, Ill. However, the farm's owner says tests by health authorities all came back negative for salmonella.
