As the scale of the nationwide outbreak of Salmonella Heidelberg started to sink in Thursday — along with the stunningly large recall of 36 million pounds of ground turkey, much of it probably already eaten — there were a number of moments that made a careful listener need to stop and just think.

First was the sheer size of the announced recall, which food-policy reporter Tom Philpott estimated would fill several floors of the Empire State Building, and Will Balsham suggested via Twitter would fill miles of tractor trailers.

Second was the confirmation, from the Centers for Disease Control and Prevention, that the Salmonella samples recovered from patients are resistant to several antibiotics — ampicillin, tetracycline and streptomycin — that are commonly used not only in human medicine, but in agriculture as well. (The strain still responds to Cipro, a fluoroquinolone; ceftriaxone, a cephalosporin; and trimethoprim-sulfamethoxazole, a drug combination best known under the name Bactrim.)

Third was the government’s measured response to the unfolding of the outbreak. In a Thursday morning phone briefing, reporters pressed CDC and USDA Food Safety and Inspection Service (FSIS) representatives to explain why  Cargill Inc. was only contacted by federal representatives last Friday, when one arm of the investigation showed a turkey connection a week earlier and a separate federal database was recording provocative results in May.

But the biggest revelation may have been that, in strict legal terms, there may have been no wrongdoing in the distribution via turkey of the drug-resistant strain that has killed one person and sickened 78 — because Salmonella, the organism in question, is not classified by the federal government as something that is illegal to distribute.

In food-safety regulation, there’s a concept called “adulterant”, a substance that by law may not be distributed in food. When you hear the word, what springs to mind is probably Upton Sinclair-style additives such as sawdust and plaster. But foodborne disease organisms can be adulterants also. The best-known is undoubtedly E. coli O157, which was declared an adulterant in 1994, one year after the Jack-in-the-Box outbreak that killed 4 children and put 171 in the hospital.

Salmonella, though, is not an adulterant. The federal government has never named it one, despite pleas from nonprofit organizations such as the Center for Science in the Public Interest, which in May filed a petition with the USDA that specifically asked for drug-resistant Salmonella — the organism in this outbreak — to be declared an adulterant so that extra preventative steps could be authorized according to law. The USDA has not acted on the request.

(Resistant Salmonella isn’t the only outbreak-causing organism that activists believe should be declared an adulterant. Crusading food-safety attorney Bill Marler — who began his career representing the Jack-in-the-Box victims — since 2009 has been pressing the federal government to add other major E. coli strains to the adulterant category, including the E. coli O104 that caused widespread illness in Europe this summer.)

Declaring an organism an adulterant doesn’t only make it illegal for food producers to distribute. It also imposes a duty on federal food-safety agencies to detect its presence in food so as to prevent its distribution. When USDA accepted E. coli O157 as an adulterant in 1994, the agency created a sampling and testing program that operates within the food-production industry to detect the organism and stop it before it goes out the plant loading dock. No such program exists for resistant Salmonella, even though there have been 29 known outbreaks of resistant Salmonella in food in the United States since the 1970s.

It’s important to say that there is some federal detective effort aimed at finding disease-causing and resistant organisms in the food supply. It was that effort that detected this Salmonella strain in food over the past few months and allowed the contaminated product to be linked to the emerging outbreak. But without a declaration of adulteration, the effort legally can only focus on the organism after the fact: after it has contaminated the meat, left the plant, and come to notice by making people sick.

Here’s what that looks like, from the annual report of the joint federal program, NARMS (National Antimicrobial Resistance Monitoring System) that performs routine sampling of retail meat to see what organisms are present. This is the graphic, from the 2009 report, that presents drug-resistant Salmonella in turkey. The letters across the bottom represent different classes of antibiotics. The higher the bars, the more resistance there is. NB: if you look carefully at the different colors, you’ll notice that in 2008 and 2009, antibiotic resistance has been as high as it has ever been.

Last night, I asked Marler what the USDA should be doing to change the trend of resistant organisms spreading through food production. He said: “FSIS should consider all pathogenic bacteria and viruses as adulterants just like the FDA does. But if we can’t get FSIS to act like FDA, they should at least deem (non-O157) E. coli and antibiotic-resistant Salmonella adulterants.”

Which echoes what CSPI said when they launched their petition for outlawing resistant Salmonella two months ago: ““USDA should take action before people get sick, and require controls and testing for these pathogens before they reach consumers… It’s time to move to a more preventive system of controlling the risks at the plant and on the farm.”

UPDATE: Consumers Union points out this morning that not only do federal rules implicitly allow Salmonella — they don’t allow USDA to force a recall when Salmonella or another disease-causing organism is discovered. (The Food Safety Modernization Act passed recently gives mandatory recall authority to FDA, but not USDA.) Jean Halloran, CU’s director of food policy initiatives, said in a statement: “The current USDA ground turkey standard, which allows 49.9 percent of samples in a test run to be positive for Salmonella, is unacceptable and clearly ineffective as a tool for food safety.”

See Also:

Salmonella: PHIL, CDC