Managing for Salmonella Continues to Present Challenges
Despite decades of efforts to control contamination rates, Salmonella has long been the most common illness-causing bacteria in food, and it remains the leading cause of death and hospitalization from foodborne illness in the U.S.
Today, Salmonella is still one of the top food safety concerns for the food industry, government regulators, and consumer advocates, and it’s regularly the leading topic at food safety conferences, including the National Food Policy Conference, which recently hosted a panel discussion on the latest attempts to manage the threat of Salmonella.
One thing that makes Salmonella so challenging is that we’re still discovering new serotypes all the time, said Dr. David Goldman, chief medical officer at the U.S. Department of Agriculture (USDA). Salmonella is represented by about 2,500 serotypes, 60 percent of which cause illness in humans.
The U.S. Centers for Disease Control and Prevention (CDC) is still discovering new Salmonella serotypes on almost a weekly basis, Goldman said.
At the same time, Salmonella outbreaks are continually linked to food products previously not associated with the bug. Just in 2014, Salmonella outbreaks were traced back to cucumbers, sprouted chia seeds, and pet bearded dragons, to name a few.
Health officials have been working for decades to get Salmonella infection rates under control, but with little to show for it.
In 2000, the federal government set a goal of reducing Salmonella infection rates from the 18 in 100,000 people it affected in 1987. They were successful, taking measures that lowered that rate to 13.6 per 100,000 by 2000.
But they might have been too quick to celebrate. For 2010, the feds set a very optimistic goal of 6.8 Salmonella cases per 100,000. Instead, the rate went back up to 15 per 100,000.
Now, the health objective for 2020 is 11.4 cases per 100,000 — a 20-percent reduction from the 15.2 per 100,000 seen in 2013.
By comparison, rates of E. coli O157:H7 have steadily declined through years of intervention measures, dropping in 2013 to around 30 percent of the rates seen in 1996.
USDA-regulated foods — namely poultry, beef and pork — account for roughly 34 percent of all recorded Salmonella cases. As a result, in 2011, USDA set stricter performance standards for Salmonella in poultry.
Eighty percent of chicken purchased by consumers is in cut-up parts, which previously did not have performance standards. USDA found that about 24 percent of chicken parts carried Salmonella and proposed measures to reduce that to 15.4 percent in chicken parts and 13.5 percent in ground turkey.
Now the agency is considering Salmonella performance standards for ground beef and pork cuts as well.
Comparing the struggle to control Salmonella to efforts that successfully led to E. coli reductions, it’s important to understand that Salmonella simply behaves in ways that make it more difficult to control, said Scott Eilert, vice president of food safety, quality and regulatory for Cargill Inc.
With E. coli, the main food safety lesson is simple: Keep the meat clean, Eilert said, meaning that the most important measure is ensuring that fecal material from the intestines doesn’t contaminate the carcass.
With Salmonella, it isn’t that simple. The bug can transfer to the lymph nodes of cattle, or into the inner tissues of a broiler bird.
Learning from previous ground turkey recalls, Cargill now tests all of its ground turkey for Salmonella before sending it out to stores. If the levels pass a threshold the company considers too dangerous, the turkey is diverted to a product line that gets cooked before reaching the marketplace.
The company is continually looking for similar strategies with other products to drive down the chances of encountering a Salmonella problem, Eilert said.
But because Salmonella in poultry is considered a natural hazard — unlike E. coli in ground beef, which is considered an adulterant — no companies are currently required to take the measures that Cargill does to help prevent their customers from being sickened.
USDA can’t do anything to stop companies in the event of a severe Salmonella contamination, either. That’s why Foster Farms chicken was able to sicken hundreds of customers with Salmonella over a 17-month period in 2013 and 2014 — no one could order them to stop over Salmonella, and the company didn’t volunteer to do so.
Of course, consumer groups are pushing for USDA and Congress to do more. For one, many are urging the agency to give adulterant status to the most virulent strains of antibiotic-resistant Salmonella.
They’re also pushing for Congress to grant USDA the authority to issue recalls over Salmonella outbreaks.
“That would go a long way toward giving the USDA the ability to deal with situations like what we saw during the Foster Farms outbreak,” said Jean Halloran, director of food policy initiatives at Consumers Union, the nonprofit arm of Consumer Reports.
Failing that, the U.S. poultry industry could always try following Denmark’s lead. After accepting its serious Salmonella problem some 25 years ago, the country developed a Salmonella action plan to tackle it head-on.
The original goal was to reduce rates of the bug in flocks to 5 percent, but that was soon revised to a zero-tolerance level for Salmonella. And it actually worked.
“In 2002, the plan was handed over to the industry, who continue to finance and administer the plan,” said Anna de Klauman, minister councilor for food and agriculture at the Danish Embassy in Washington, D.C. “We’ve had no record of Salmonella in Danish broilers in the past three years.”
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