Although a federal investigation into salmonella-tainted tomatoes has not yet identified a specific source for the contamination, officials are now focusing their traceback efforts on one cluster of nine cases in one location.

"The cluster is linked to the same geographic location, and all [victims] are appearing to have consumed similar types of tomatoes," Dr. David Acheson, associate commissioner for food protection at the U.S. Food and Drug Administration, was quoted as saying in press reports. "We're not there yet on the cluster, but I'm hopeful that this is our most fruitful lead to date on the traceback."

Acheson and other officials declined to divulge the location of the cluster or comment on whether it was the same one reported in an e-mail by a top FDA official on Friday, which involved nine victims who ate at two restaurants in the same chain.

Meanwhile, officials at the U.S. Centers for Disease Control and Prevention said the number of people sickened in the outbreak stood at 277, an increase of 49 over last week's count; with 43 hospitalized. The number of states reporting illnesses also increased by five, plus Washington, D.C.

In related news, the United Fresh Produce Association (United Fresh) and the Produce Marketing Association (PMA) sent a joint letter yesterday to the Secretary of the U.S. Department of Health and Human Services (HHS), requesting a meeting with government organizations including the Food and Drug Administration and the Centers for Disease Control and Prevention.

In a co-signed letter to HHS Secretary Michael Leavitt, Tom Stenzel, United Fresh president and Bryan Silbermann, and PMA president, said: "In the rare but critical cases where outbreaks do occur, we simply must do a better job to remove any threat to public health as soon as humanly possible, and isolate potential problems quickly to ensure ongoing consumer confidence in the vast supply of healthy, fresh produce available across the country."

The association chiefs called for a meeting to explore solutions that would speed and streamline outbreak identification and management. With government's expertise in outbreak identification and industry's expertise in understanding the produce supply chain, crisis management systems should be reviewed in advance of outbreak investigations, rather than having industry and government reinvent the process each time an outbreak occurs, they said.

"Nothing is more important to the produce industry than delivering to consumers the safest, healthiest and most nutritious fresh produce possible," the trade officials said. "No one in public health nor industry can be satisfied with an outbreak that went undetected for so long, nor a traceback investigation that has left consumers scared about the safety of all fresh tomatoes and will likely cost more than $100 million to tomato growers, packers and retailers whose produce was never contaminated. We simply must work together to do better."

To read the letter, the tomato outbreak pages on visit either association's Web pages: www.pma.com or www. unitedfresh.org.