WASHINGTON - The salmonella strain linked to a nationwide outbreak has been found in irrigation water and in a sample of serrano peppers at a Mexican farm, federal health officials said yesterday.
Dr. David Acheson, the Food and Drug Administration's food safety chief, called the finding a key breakthrough as did another health official.
"We have a smoking gun, it appears," said Dr. Lonnie King, who directs the center for food borne illnesses at the Centers for Disease Control and Prevention.
The FDA advised consumers to avoid raw serrano peppers from Mexico, in addition to raw jalapeno peppers from Mexico.
The outbreak sickened more than 1,300 people across the country and cost U.S. tomato growers more than $300 million.
Dr. Acheson told a subcommittee of the House Agriculture Committee that the same strain of salmonella Saintpaul that caused the outbreak was found in irrigation water and serrano peppers on a Mexican farm. A contaminated jalapeno pepper had been traced previously to the Mexican grower.
Lawmakers on the House panel questioned Dr. Acheson and Dr. King about why it has taken since May to track down the source of the food poisoning and whether they were mistaken all along in associating the illness with tomatoes.
The warning from the federal agencies led to a mass removal of tomatoes from groceries and restaurants and cost the industry more than $300 million, subcommittee chairman Dennis Cardoza (D., Calif.) said.
He asked Dr. Acheson if a single contaminated tomato was ever found.
"No," Dr. Acheson said.
But he refused to completely clear tomatoes. He said tomatoes as well as jalapeno and serrano peppers were grown on the Mexican farm with contaminated irrigation water and that tomatoes were processed through the same packing center so it is "plausible" that some illnesses were caused by tomatoes.
Mexican officials rejected the latest FDA findings and said the sample was from stagnant water in a tank holding rainwater, not water used to irrigate peppers.
"What they took was a sample from soil after the harvest. That is not scientifically valid in any part of the world," said Enrique Sanchez, the Agriculture Ministry's director of food health.
The Mexican Embassy in Washington earlier said the Mexican government had taken the precautionary measure of suspending exports of produce from the suspected company.
Mexican officials had repeatedly denied that the outbreak, originally blamed on tomatoes but later traced to peppers, could be traced to Mexican farms.
U.S. congressional investigators have accused the FDA of mishandling the case.
The probe was slowed partly because FDA investigators were unfamiliar with the workings of the tomato industry and were reluctant to share information, industry representatives told the House panel.
"For weeks and weeks, investigators were on the trail of the wrong product," Thomas Stenzel, president of the United Fresh Produce Association told the House Agriculture Committee.
Lawmakers are considering a range of reforms including improving communication between investigators and the industry, imposing standards for good agricultural practices, and improving traceability.
"You could describe our current food safety system as 'outbreak roulette,' " Mr. Cardoza said. "One spin of the outbreak wheel, and your industry may be bankrupt, your loved ones sickened."