Are tomatoes a salmonella red herring?

ATLANTA — A salmonella outbreak that has sickened 810 Americans may still be making people ill, and it may not be linked to tomatoes after all, federal health authorities said Friday.

Tomatoes still have the strongest association with the outbreak, said Patricia Griffin of the Centers for Disease Control and Prevention. But investigators are now looking at other ingredients that may be in foods eaten by salmonella victims, which include such popular Tex-Mex dishes as guacamole and fresh salsa.

They're also investigating whether tomatoes from growing regions cleared in the outbreak could be picking up the bacteria in a packing house or distribution warehouse and causing infections in people who think they're buying safe tomatoes.

"Whatever the produce item is that's causing the illness is possibly still out there making people sick," said Griffin, chief of the CDC's Enteric Diseases Epidemiology Branch.

For now, the U.S. Food and Drug Administration has not changed its advice. The FDA says that cherry and grape tomatoes and tomatoes on the vine are safe to eat, and that it's also OK to eat round red tomatoes and Roma, or plum tomatoes, from approved growing regions.

The FDA cleared areas that weren't producing tomatoes when the outbreak began April 10. Tomatoes from some of those regions are going through the same packing houses and distribution centers that the FDA is checking as part of its attempts to trace back the contaminated tomatoes, David Acheson, the agency's associate commissioner for foods, said in conference call with reporters.

At this time, the FDA has no indication that cleared growing regions have any connection to the outbreak, Acheson said.

That could change.

"We need to re-examine all parts of this system and make sure the consumer message is still solid," Acheson said.

In the past week, investigators have taken 1,700 samples of water, tomatoes and soil from farms, packing houses and warehouses in Mexico, Florida and other parts of the United States, looking for the Salmonella Saintpaul strain that is causing the illnesses. So far, no bacteria have been found.

"If it's not tomatoes, we've gone through a lot of agony," said Charles Hall, executive director of the Georgia Fruit and Vegetable Growers Association.

Warnings about the outbreak have scared some buyers away from any tomatoes, and Georgia farmers are seeing prices drop as they approach their peak production season.