June 12 (Bloomberg) -- New infections are being reported daily from the outbreak of tainted tomatoes that has sickened at least 167 people in the U.S., an official with the Centers for Disease Control and Prevention said.

``We are still seeing cases,'' said Ian Williams, chief of the CDC's team that investigates outbreaks, during a conference call yesterday with reporters. ``And we would characterize the outbreak at this point as still ongoing.''

The Food and Drug Administration is making progress in its search for the source of the outbreak, David Acheson, the agency's associate commissioner for food, said on the call. Growers and state regulators criticized the pace of the FDA's investigation as consumers and restaurants leave tomatoes out of their salads and off of their sandwiches.

``An entire industry has come to a standstill and consumers are affected by the publicity,'' said Kathy Means, vice president of the Produce Marketing Association, based in Newark, Delaware, in an e-mailed statement. ``That is why we must find a way to speed this up -- both for public health and the industry.''

Tomato farmers generate U.S. sales of $1.4 billion a year, according to Amy Philpott, a spokeswoman for the Washington- based United Fresh Produce Association, whose group represents businesses in every stage of the supply chain.

`Losing Millions of Dollars'

``Up until yesterday, when Florida started shipping again, we were losing millions of dollars a day,'' Philpott said in a telephone interview ``There's no reason why the trace-back investigation shouldn't go a lot quicker, and we need to figure out how to fix it.''

The FDA says that raw red plum, red Roma and round red tomatoes shouldn't be handled or eaten at all. Neither washing nor cooking the produce will eliminate the bacteria, the agency said on its Web site. The agency didn't identify the source of the contamination; some bacteria may be in the water or soil where the food grows, or it may be introduced during harvesting or storage, the FDA said.

Salmonella bacteria can cause diarrhea, abdominal pain and vomiting, according to the FDA.

The FDA has so far cleared 23 states, Puerto Rico and most of Florida as areas where the tainted tomatoes couldn't have been produced based on harvesting times and shipping patterns. Canada and five other countries have been ruled out. Mexico and several states in the southwestern U.S., where the outbreak originated, haven't been cleared.

23 Hospitalizations

The first case was reported to a doctor in New Mexico on April 23, and that state and Texas have seen the most cases overall, Acheson said. The tomatoes are believed to be linked to 23 hospitalizations in 17 states, according to the FDA.

``Obviously the critical question is where did these specific tomatoes come from, and we're not quite there yet,'' Acheson said. ``At this point today, we don't know where they came from.''

The 167 cases reported by the CDC and FDA include only those the agencies have confirmed. State and local health officials are getting new laboratory reports of the strain of salmonella involved in the outbreak ``on a daily basis,'' said Williams of the Atlanta-based CDC. These may not be newly sick patients because lab results can take two to three weeks, Williams said.

People who ate tomatoes at home as well as in restaurants have reported falling ill, he said.

`More Out There'

``There's likely many more infections out there that are unrecognized and have not been reported yet to the CDC,'' Williams said.

The FDA recommended that consumers limit their tomato consumption to those that aren't the likely source of illnesses, such as cherry tomatoes, grape tomatoes and those sold with the vine still attached.

Tomato farmers in Mexico have seen a slowdown in orders since the first reports of salmonella, said Cesar Campana, president of the Mexican Association of Protected Horticulturists. His group represents growers in 21 states that produce about a third of the nation's crop. Mexico accounts for 84 percent of tomato imported to the U.S., according to the United Nation's Food and Agriculture Organization.

``Of course it is affecting business,'' Campana said in a telephone interview. ``Supermarket chains are already rejecting Mexican varieties.''

Acheson defended the pace of the FDA's investigation, which also has been criticized by some lawmakers. Tomatoes don't come in bar-coded packages that can be easily traced, he said, and every link along the supply chain -- from supermarkets to suppliers to distributors -- can get tomatoes from several sources.

``As you go back here, each set of questions just multiplies out into a fan of information that has to be sorted through to understand where the links cross over,'' he said.

To contact the reporter on this story: Alex Nussbaum in New York anussbaum1@bloomberg.net.

Last Updated: June 12, 2008 07:44 EDT