As Tomato Salmonella Cases Rise, FDA Chases Leads

The Centers for Disease Control and Prevention raised the number of cases of salmonella linked to raw tomatoes to 552 people in 32 states, as Food and Drug Administration investigators fanned out to try to determine where in the supply chain the tomatoes were contaminated.

David Acheson, the FDA's associate commissioner for foods, said some of the contaminated tomatoes were grown on a number of farms in Florida and Mexico. But he cautioned that the farms aren't necessarily the source of the contamination; it could have occurred in places where the tomatoes were packed or stored, he said.

Associated Press

Workers separate tomatoes at a market in Mexico City.

In a conference call Friday, Dr. Acheson said that it would be "extremely unlikely" for this outbreak, which involves the rare and virulent Saintpaul strain of salmonella, to have originated simultaneously in two separate places. The FDA believes the contamination occurred at a single point "somewhere in the distribution chain" as tomatoes made their way from farms in Mexico or Florida to the dinner table, Dr. Acheson said. So it is sending as many investigators as needed to Florida and Mexico and along the supply chain "to get the job done."

He said the agency has been working with health officials in Florida and Mexico, along with Texas, which had a cluster of cases and the largest number of reported cases, 265.

The FDA also is working with the CDC, other federal agencies and states, but Dr. Acheson said that "we got nothing to suggest that [the contamination] is deliberate."

On Wednesday, the CDC reported 383 cases of salmonella in 30 states; the first case occurred April 10, and the most recent was on June 10. Some states recently completed test results, which contributed to the jump in cases.

Dr. Acheson said the FDA "isn't aware of" any illnesses of the Saintpaul strain in Mexico, but he said he is also not sure whether the farms exporting tomatoes to the U.S. also sell them in Mexico.

Write to Jane Zhang at Jane.Zhang@wsj.com¹