Source of tainted tomatoes still unknown

"Obviously the critical question is, where did these specific tomatoes come from? And we're not quite there yet. At this point today, we don't know where they came from," said David Acheson, the Food and Drug Administration's associate commissioner for foods.

New reports of illness are still coming in, said Dr. Ian Williams of the Centers for Disease Control and Prevention in Atlanta. "We are still seeing cases," he said. "And we would characterize the outbreak at this point as still ongoing." Here is the latest information.

Has the FDA found the source of the tainted tomatoes?

No, the investigation continues. Health officials are hampered by the fact that tomatoes don't carry bar codes. Suppliers might get the fruit from multiple farms, and that makes it hard to figure out where the contamination started.

Did the people who became sick consume their tomatoes at a restaurant or while eating at home?

Both, and that has also made the probe difficult for officials. In many food-borne-illness outbreaks, victims can be quickly grouped by having eaten a certain brand of food or having frequented a specific restaurant or chain. This time the cases vary widely.

Any suspects?

Investigators are focusing on tomatoes from central Florida and Mexico -- regions that would have supplied the bulk of the fruit on the market in April, when the outbreak started. They also have ruled out all of California and northern Florida, which also are big tomato-growing regions. Those areas were not harvesting at the time of the outbreak and could not have been responsible.

Is it safe to eat tomatoes?

Yes. FDA officials say grape and cherry tomatoes and tomatoes sold attached to the vine are safe to consume. Any tomatoes grown in California also can be eaten, regardless of the variety.

What should I avoid?

For now, stay away from the standard round tomatoes and also plum tomatoes, which in some stores are sold under the name Roma.

How did the FDA figure out there was a problem?