FORT LAUDERDALE, Fla. (MCT) — Federal officials said Friday that tomatoes grown in Florida or Mexico caused at least some of the salmonella outbreak that has sickened 552 people, and they are sending teams this weekend to inspect every point in several states where the produce was handled.

The contamination could have occurred on one of several farms in the two major tomato-growing areas, or at packing houses, warehouses, distribution centers or other shipping points from the field to the consumers, health officials said.

Tomatoes being produced when the illnesses began in mid-April would have come from fields in the southern half of Florida, the largest lying outside Fort Myers and also in Miami-Dade and Palm Beach counties. Dr. David Acheson, an associate commissioner at the Food and Drug Administration, declined to say how many or which farms had been linked to the tomatoes or which would be visited.