The US Food and Drugs Administration (FDA) has revealed that it has completed the traceback on some of the tomatoes involved in the Salmonella Saintpaul outbreak to farms in Florida and Mexico, although the group insists that it has yet to complete its investigation and has not identified the source.
The FDA has reported that it is working alongside authorities in Mexico and Florida, conducting joint investigations to sample domestic and imported product.
"Now that the FDA has identified the paths that those tomatoes have travelled between the farms to the consumers, we will be looking along all those pathways to see where the contamination occurred," said the body's associate commissioner David Acheson.
The Center for Disease Control and Prevention (CDC) has said that there are now 552 known reports of people infected with Salmonella since the first case was discovered on 10 April. Thirty-two states and the District of Columbia have been affected by the outbreak.