Produce businesses also are hoping that the U.S. Food & Drug Administration can identify the source -- whether a particular field or handler -- before the tomato market takes a big hit.
As of June 3, New Mexico and Texas had confirmed 57 cases of Salmonella poisoning, 17 of which resulted in hospitalizations, but no deaths. Disease investigators are looking at 29 more Salmonella cases in Arizona, Colorado, Idaho, Illinois, Indiana, Kansas, Virginia, Wisconsin and Utah that may be linked to the outbreak.
New Mexico first announced on May 31 that tomatoes were a likely source of the outbreak.
"We have determined that eating uncooked tomatoes is the likely source of this outbreak, and we hope to provide more specific information about the type of tomatoes as the investigation proceeds," New Mexico Health Secretary Alfredo Vigil said in a statement.
Health authorities confirmed the outbreak strain Salmonella serotype Saintpaul through DNA fingerprinting. State officials narrowed the search to tomatoes sold at foodservice and retail after conducting patient interviews.
FDA followed with a June 3 nationwide notice warning New Mexico and Texas consumers not to eat certain varieties of tomatoes, including raw red plum, red Roma, and traditional round red tomatoes. Consumers can eat cherry tomatoes, grape tomatoes, tomatoes sold with the vine still attached, and tomatoes grown at home, federal officials said.
"We still don't know if the tomatoes were domestic or foreign grown," said FDA spokesman Sebastian Cianci. "We hope to nail this down in the next few days."
While FDA conducts its traceback, businesses find themselves in the frustrating position of waiting for FDA to pinpoint a particular tomato or region through a pain-staking traceback process.
The Produce Marketing Association is talking with retailers in the two affected states to see where they sourced tomatoes during the last six weeks. At this point, it could be Israel, Holland, Mexico, Canada, Florida or several other locations, said Kathy Means, the association's vice president of government relations. "We're trying to help FDA narrow the scope."
Right now, though, there's no recall, said Ms. Means, and health officials are still seeing illnesses, so it's not over yet. Illnesses have been reported from April 23 to June 1. She said that retailers are heeding FDA's advisory and not offering round red, Roma and plum tomatoes in Texas and New Mexico.
Industry sources said that the six-week illness period may point to more than one picking field, and the tainted tomatoes must have been shipped between mid-April and mid-May.
In a June 4 industry conference call, PMA and the United Fresh Produce Association fielded questions from concerned tomato traders looking for advice. Customers are in a panic in the Texas area, said one company representative, who expressed frustration that the source had not been pinpointed.
Tomato-associated Salmonella outbreaks have increased in frequency and magnitude in recent years, and the tomato industry has been responding with new safety guidelines.
"The tomato industry has been very proactive with new regulations that kicked in June 1 in Florida," said Ms. Means.
California is working on a similar program, and the North American Tomato Trade Work Group, which represents producers in Mexico, Canada and the United States, and is releasing a second edition of its best practice guidelines for the tomato supply chain, she said.
FDA began a Tomato Safety Initiative last year and sent investigators to Virginia and Florida, two of the the nation's larger producers of fresh tomatoes, to pinpoint the practices that may lead to food-safety problems. Large outbreaks in 2005 and 2006 were tied to tomato fields in Florida, Ohio and Virginia.
After conducting farm assessments, FDA plans to wrap up data collection this year in its probe into whether growers are following Good Manufacturing Practices and if new policies are needed.
Ms. Means said that FDA is showing more sensitivity to the produce industry and is keeping groups apprised of the investigation through daily conference calls, as well as letting companies help the agency in gathering information.
In the June 3 press release, FDA added language to show that the agency was trying to narrow its warning so as not to tarnish the entire tomato industry - a criticism that still lingers after the blanket warning that crushed the spinach industry during a recent outbreak.
"FDA recognizes that the source of the contaminated tomatoes may be limited to a single grower or packer or tomatoes from a specific geographic area," the agency said in a statement. "FDA also recognizes that there are many tomato crops across the country and in foreign countries that are just becoming ready for harvest or will become ready in the coming months."
Most of the advisory was focused on people in New Mexico and Texas, said FDA's Mr. Cianci. "We're not trying to alarm people in Massachusetts."