Federal officials are having difficulty providing consumers with information on two recent food-borne illness outbreaks. Investigators are still searching for the source of an ongoing salmonella outbreak, and officials have been unable to provide detailed information for consumers on a batch of E. coli-contaminated beef, which has spread to a number of states across the country.

More than a month after announcing a nationwide warning against the consumption of certain types of raw red tomatoes, and almost three months since the first cases of salmonella were reported, the U.S. Food and Drug Administration (FDA) still has not pinpointed the source of the contamination.

FDA announced the warning June 7 after more than 100 consumers had been sickened by a rare strain of salmonella, Salmonella Saintpaul. FDA's preliminary investigation linked the salmonella to red plum, red Roma, and/or round red tomatoes.

But the FDA said last week it was expanding its investigation to other types of produce commonly served with tomatoes, particularly ingredients in salsa like cilantro, jalapeno peppers, and other types of hot peppers, according to the Associated Press. FDA officials have emphasized that tomatoes are still the lead suspect in the outbreak, but many health officials are suspecting additional produce sources, because since the outbreak began in April, tomato production has shifted geographic locations. Experts say it is unlikely that two separate locations would have the same unusual salmonella strain.

Meanwhile, hundreds more cases of the outbreak have been reported. The latest tally from Centers for Disease Control and Prevention (CDC) is 943 illnesses. Experts believe the actual toll is probably much higher, possibly in the thousands, because many cases of food poisoning go unreported. With CDC revising its figures every few days, neither the spread nor intensity of the outbreak appears to be abating.

The complexity of the supply chain — which shuffles tomatoes and other produce across state and national boundaries for processing, packaging, and distribution — makes identifying the source of this or any other food-borne illness outbreak a major challenge for FDA. A retailer may buy produce from multiple distributors, each of which likely collects a variety of goods from multiple growers. Adding to the difficulty might be the faulty memory of those who become ill.

Critics say the FDA itself is at least partially to blame. Two consumer groups, the Center for Science in the Public Interest (CSPI), and the Consumer Federation of America (CFA), wrote to FDA commissioner Andrew von Eschenbach chiding his agency for its lax record on produce safety. "This massive outbreak might have been prevented if FDA had responded to the numerous produce outbreaks that preceded it," the letter says.

The groups say FDA does not have the necessary safeguards in place to prevent and track food-borne illnesses. They said "source traceability for produce, written food safety plans for farmers, processors, and packinghouses, and tighter controls on repacking" are necessary but lacking, despite repeated pleas from food safety advocates.

Regulators are also investigating an outbreak of E. coli after a batch of beef was linked to at least 30 cases of the disease in Ohio and Michigan.

While federal officials quickly identified the source of the contaminated beef — Nebraska Beef in Omaha — consumers are still left largely unprotected. The contaminated beef has been further processed and possibly incorporated with other beef, making it difficult to track the ultimate location of the contaminated product.

Initially, the beef recall included only half a million pounds and covered shipments sent to processors and wholesalers in Colorado, Illinois, Michigan, Nebraska, New York, Pennsylvania, and Texas. The Food Safety Inspection Service (FSIS) — the unit of the U.S. Department of Agriculture charged with regulating meat, poultry, and egg products — announced the recall June 30.

In the recall announcement, FSIS disclosed the USDA approval code for the batches of contaminated beef. However, FSIS says product packaging will no longer bear the code since the shipments "were further processed into ground beef."

When FSIS announced July 3 that the recall had been expanded to 5.3 million pounds, it gave no further indication as to where the Nebraska company had shipped the contaminated beef or how processors, wholesalers, retailers, and consumers could identify it. FSIS does advise consumers to make sure they cook beef to an internal temperature of 160 degrees Fahrenheit.

Although it is required to physically inspect all meat and poultry destined for commerce, FSIS has been having increasing trouble ensuring the safety of those products. Over the years, FSIS's inspection staff has been dwarfed by the growing size of the meat and poultry industries, according to an OMB Watch analysis. In 1981, FSIS employed about 190 workers per billion pounds of meat and poultry inspected and approved. By 2007, FSIS employed fewer than 88 workers per billion pounds, a 54 percent drop.

CSPI and CFA, the groups that wrote to the FDA commissioner about the salmonella outbreak, are calling for federal requirements that produce be marked in order to help investigators trace the source of contamination. According to their letter, "Those marks should be specific enough to extend all the way back to the farm of origin." Produce should also bear more informative labels to enable consumers to trace food from their dinner tables all the way back to the farm, the groups say.

At least two bills in Congress focus on the issue of food tracking. One bill (H.R. 3485), introduced by Rep. Diana DeGette (D-CO), would require the government to implement a tracking system "for all stages of manufacturing, processing, packaging, and distribution of food." Another bill (S. 1292) would require a similar system but apply only to meat and poultry products. Neither of these bills, nor the approximately ten other bills aimed at improving food safety, have cleared the committee stage.