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From: Food Quality & Safety magazine, February/March 2008

The Long, Hard Road to Beef Safety

After years of decline, beef recalls because of E. coli spiked in 2007

by Steve Sayer

The beef industry has long been in a race to keep up with its nemesis, Escherichia coli O157:H7. In 2007, it seemed as if the bacterium was winning. Compared with recent years, 2007 saw a colossal jump in the number of recalls due to beef products tainted with E. coli O157:H7.

At the end of December, the United States Department of Agriculture (USDA) announced its 22nd recall of meat tainted by the bacterium. What is the cause of this spike on everyone’s histograms and control charts? What has gone awry in the beef industry? And what has been happening with the USDA, which, until 2007, seemed to have corralled this enteric pathogen?

Unfortunately, these are questions that scientists, regulators, and processors still can’t answer. The rains in the high plains, the droughts in the South, and the nationwide heat waves experienced in 2007 were cited inside industry circles, as were possible mutations of the organism. A number of areas, however, are being reviewed and re-evaluated. As food experts in and out of academia have continued to reiterate, controlling the pathogen involves the long, winding, and sometimes rocky road that encompasses the farm-to-table continuum.

Promise, Then Disaster

What makes 2007’s 22 recalls so shocking is that there were only eight recalls involving O157:H7 in 2006, five in 2005, and six in 2004. Just when it appeared the beef industry was catching up with its nemesis using innovative science-based interventions, disaster struck.

The final O157:H7 recall of 2007 involved 14,800 pounds of ground beef, but even that number pales in comparison to the 21.9 million-pound recall that toppled Topps Meat Company (Elizabeth, N.J.) in September. The Topps recall has the unfortunate distinction of being the fourth-largest recall of tainted ground beef in U.S. history. The demise of Topps was also a somber reminder that this microscopic bug has the potential to kill and maim not only unsuspecting people but giant businesses as well—businesses such as Hudson Foods. Hudson shuttered its doors when 25 million pounds of hamburger was recalled after E. coli was found in the company’s ground beef in 1997. [Editor’s Note: In February, the Westland/Hallmark Meat Company recalled 143 million pounds of beef, making it the largest such recall in United States history.]

The Topps recall grew exponentially, much like bacteria in the right environment. It grew from three days’ production volume to one year’s because product was carried over day after day with no total separation cutoffs. This resulted in an inexcusable and unparalleled one-year total recall. The lack of total separation, or “cleanup to cleanup” accountability, was also the harbinger of the Hudson Foods recall a decade earlier. Unfortunately for Topps, history has an uncanny flair for repeating itself regardless of the business—or century—at hand.

In July 2007, the Food Safety Inspection Service (FSIS) of the USDA detected five positives for O157:H7 in three days. There was nothing linking the samples and no evidence of mistakes on the part of FSIS laboratories. The USDA viewed this O157:H7 spike as a singular event in the 13-year history of FSIS verification testing and deemed that beef operations might not have adequate interventions to address the degree of contamination caused by E. coli O157:H7.

Whatever the cause (or causes) of the recent E. coli O157:H7 resurgence, one element is clear. Both large and small processors have had their company’s names and reputations placed in bright neon lights on the USDA’s recall list for 2007. But perhaps it is time to look behind the scenes and scrutinize the practices of farmers, feedlots, cattle transporters, and slaughterhouses.

Back on the Farm

Eclectic food-borne pathogenic bacteria sicken more than 76 million Americans annually, in many cases after consumption of foodstuffs derived from animals. Post-slaughter intervention strategies have been shown to truncate bacterial contamination from the abattoir to the table. In spite of these proven and effective strategies, foodborne illnesses and food-related deaths occur too frequently. Strategies that expand the continuum of interventions from the abattoir back to the farm may have the greatest potential to further reduce pathogenic contamination.

E. coli O157:H7 has been described as ubiquitous in dairy and beef cattle and is present on most farms and feedlots. Feedlot cattle have a strong chance of E. coli O157:H7 contamination because most cattle are obtained from large herds. In virtually every herd, some animals are shedding O157:H7. In addition, the animals are housed under crowded conditions, with or without efficient manure removal systems, a situation that provides this organism ample opportunity to persist and multiply.

USDA research has demonstrated a difference in the prevalence of E. coli O157:H7 in heifers, cull cows, and yearling cattle. Cattle weight, seasons of the year, herd management, and feedlot practices have been shown to affect prevalence as well. In an ideal world, slaughterhouse management should consider as their source of animals for slaughter only those farms and dairies that incorporate practices that reduce carriage of pathogens.

Cattle continue to be implicated as the reservoir for E. coli O157:H7. At present, control of entry and contamination from these pathogens in slaughter establishments is based to a large extent on sanitation procedures, control of cross contamination, and treatment of carcasses for visible contamination. Its widespread prevalence in cattle is a testament to the organism’s ability to survive for long periods—for months in water trough sediments—thus providing an ongoing source of exposure to cattle.

Vaccines, Feed Strategies

Effective vaccines for cattle would help. A Canadian company has spent more than five years trying to develop an E. coli O157:H7 vaccine. The vaccine is available to Canadian producers, but in September 2007 the USDA declined to approve its use in the United States. Even if this vaccine had been approved, the risk of cross contamination with other cattle would require segregation of livestock. This intervention wouldn’t work for the burgeoning multibillion-dollar organic meat market that has emerged within the past few years, however.

Other researchers are looking at changes in diet that would make the bovine digestive system less hospitable to pathogens. Strategies would include competitive exclusion, which involves the addition of a nonpathogenic bacterial culture to the gastrointestinal tract of food animals in order to truncate populations of pathogenic bacteria. Another strategy involves the use of probiotics—applying micro-flora to reduce pathogenic bacteria in the gut.

Another issue to consider is the source of some cattle feed. A viable alternative to motor oil and gasoline is ethanol, which is derived from grains. The production of ethanol has resulted in a symbiotic relationship between ethanol producers and cattle ranchers. Ethanol plants need to dispose of the grain left over following their manufacturing process, and cattle ranchers need a cheap source of high-protein feed for their livestock. Today, a number of ethanol factories are being built next to feedlots.

Another source of feed, distillers’ grains, may be putting the public at risk. Several preliminary rounds of testing at Kansas State University (Manhattan, Kan.) recently showed that the prevalence of E. coli O157:H7 was about twice as high in cattle fed distillers’ grain compared with cattle on a diet lacking ethanol byproduct. Researchers are not sure why, but it is becoming clear that as ethanol continues to grow as an alternative fuel source, more cattle will regularly be fed distillers’ grain.

The Slaughterhouse Stop

Today, the majority of livestock are delivered to slaughterhouses by tractor-trailers, which should be cleaned after each delivery. Gross cross-contamination to livestock occurs if these delivery double-deckers and goosenecks aren’t cleaned after each delivery. In most cases, trailer cleaning is chronically neglected; it can certainly be improved upon. There are no USDA regulations requiring the cleaning of cattle trailers, either before or after transport of cattle; slaughterhouse management should require this and conduct inspections. Livestock trailers, a link in the food safety chain, are carriers of pathogens.

Cattle presented for slaughter typically come from dairy farms, beef cattle farms, or feedlots. About 80% of all cattle slaughtered in the United States come from feedlots. They include heifers, steers, yearling cattle, bulls, or cull dairy cows. When cattle arrive at the slaughterhouses, their hides and hooves are covered with mud, manure, bedding, and other materials that contain large numbers of microorganisms. The bacterial load depends on herd- or farm-management practices, transport and holding practices, and feedlot conditions and controls. Season of the year and age and type of cattle are other factors that will influence the microbial load. Hide preparation prior to slaughter is a huge task.

The slaughter, processing, and distribution of meat from culled breeding cattle and feedlot cattle differ; sampling evidence has suggested there may be differences in E. coli O157:H7 prevalence between these two types. A risk assessment by the FSIS Office of Public Health and Science and other federal agencies determined that the prevalence of E. coli O157:H7 is significantly higher for feedlot cattle than for breeding cattle. It also found that the prevalence of E. coli O157:H7 is higher for both types of cattle during the warmer months occurring from June through September than for the months from October through May.

An effective way to detect the presence of E. coli is to micro-sample carcasses. This is a good barometer for slaughterhouses to use to measure their practices because it focuses on the efficacy of their interventions. The rump, brisket, and flank are tested because these parts of the carcass are most likely to become contaminated during dressing procedures. Testing should begin with the hide and go from there, with the same carcass being trailed before and after critical control points (CCPs) and critical limits, including taking samplings in the hot boxes.

A great deal of testing and evaluation has been conducted to determine the most effective methods for removing mud, fecal matter, and other extraneous materials from the cattle’s hide prior to and after the knocking process. Inclement climates and other unique geographic and logistic conditions restrict, to varying degrees, some hide interventions that can be used before knocking.

The slaughterhouse continuum of knocking to hot boxing should be continually reassessed. Interventions such as using antibacterial cabinet sprays before hides are removed cut bacteria loads dramatically, resulting in cleaner carcasses downstream. Positive airflows and walls that completely separate hide-on and hide-off areas are imperative. Established interventions such as pre- and post-evisceration hot water and steam vacuuming, antibacterial sprays, hot water pasteurization cabinets, and hand trimming reduce or eliminate pathogens, making them the CCPs of choice for slaughterhouses. Finally, cold chain-management begins in the hot boxes, with the surface of the hanging carcasses cooled to 40°F in approximately 24 hours.

Training and Sanitation

Although many factors can be accounted for and controlled to a certain extent, slaughterhouse workers remain a huge and undervalued variable. Management must view workers as latent vectors of contamination in the otherwise sterile conditions of exposed carcasses. Training, training, and more training must be conducted regularly to combat cross-contamination concerns. Two knife, hook, and steel practices should be used at each processing station (beginning with the stickling and ending at the final trim) with alternate tools sterilized in hot water.

Employee turnover plays a starring role in the beef industry’s woes as well. Homeland Security raids (or the threat of them) have depleted the supply of experienced workers and their time-acquired skills. Employers at USDA-inspected establishments have been, and will continue to be, singled out by the Immigration and Naturalization Service for hiring illegal immigrants. Depending on the political tide of the country, this issue will remain in the forefront of the beef industry. It will affect the safe production of meat products in varying degrees at all levels of beef processing.

Another key factor is sanitation, which is certainly significant both during and after slaughter. The hot boxes are critical, as is the traffic allowed in and around the exposed hanging carcasses. Ideally, hanging carcasses should be spaced to prevent them from touching and potentially contaminating one another, as well as for cooling. The distance from the bottom of the hanging carcass to the floor should be considered as well. Flooring should be slightly sloped to prevent the formation of puddles. Schedules of rigorous environmental testing should be set, and employee handling practices and foot traffic in the hot boxes should be restricted. Finally, remember that expensive interventions are for naught if employees with free range fail to clean their gloves and regularly change their smocks when handling carcasses.

Further Stops on the Way

The vast majority of fabricators and grinders have only one CCP in their hazard analysis and critical control point (HACCP) system—the temperature of the product prior to packaging. Unless a fabricator/grinder is supplying its own meat, then these “isolated further processors” are relying on prerequisite programs daisy-chained with their HACCP programs and those of their suppliers. Some prerequisite programs may require just an annual letter of guarantee from their suppliers, one that usually states the overused rote motto, “validated interventions have shown a reduction/elimination of E. coli O157:H7.” More prudent further processors, on the other hand, are requesting a biannual letter of guarantee and a certificate of compliance from a laboratory approved by the Association of Analytical Communities that employs the composite sampling testing standards of the USDA for E. coli O157:H7.

In October 2002 the FSIS issued a Federal Register (FR) Notice that outlined adulteration considerations regarding intact and non-intact beef products. This mandatory HACCP reassessment was the result of new data from a USDA testing methodology that identified increased prevalence of O157:H7 on live cattle coming to slaughter. In addition, the FR Notice described at length the USDA’s expectations regarding the appropriate use of prerequisite programs. In May 2005 the USDA issued a second FR Notice outlining adulteration considerations regarding mechanically tenderized and enhanced beef products. Three O157:H7 outbreaks were linked to such products that year.

The USDA believes some of the factors that may have contributed to the 22 recalls in 2007 occurred because further processors—fabricators and grinders using mechanical tenderizing, enhancement by tumbling, or injection of beef products, for example—did not serve their own best interests by failing to take into account USDA objectives contained in the October 2002 and May 2005 FSIS FR Notices. In short, companies were not following their own prerequisite programs regarding testing of incoming or finished products, including bench trim derived from primal cuts and thrown into the grinding mix.

Another reason for the spike in O157:H7 detection is that many parties, including the USDA, are testing more meat. Customers of raw beef trim suppliers are increasingly requesting USDA Robust N-60 testing techniques on boneless beef trimmings. N-60 robust testing uses 375-gram composite samples of 12 pieces of carcass surface tissue, sliced 4 inches long by 1/8-inch thick by 2 inches wide. The samples are taken from five bins, and the tests are repeated four more times, for a standard load of 20 combo bins. (The industry/government size standard of composite sampling used to be 25 grams and then became 75 grams before being boosted to 325 grams.) A certificate of authenticity (COA) from a customer-approved laboratory is completed and sent with the load. In some instances, customers now perform their own in-house testing using USDA robust N-60 testing protocols, in spite of their suppliers’ COAs.

Even with these precautions, a form of Russian roulette continues to be played as isolated further processors rely on the integrity of their beef, from the product’s delivery to their facility all the way back to the farmer. If their end product is baseline tested by the USDA or sampled by a state health department official, as was done at the Topps Meat Company by the New York Department of Health, then their businesses are at the mercy of all prior interventions, including any mishandling that might have occurred.

The End of the Road

In the end, there is no such thing as zero risk for any foods, and it is quixotic to think so. As things stand, it’s a safe bet that the road to beef safety will continue to be difficult, with processors and their suppliers occasionally breaking down or even crashing. Besides advising consumers ad infinitum that they must cook hamburger meat thoroughly, two silver bullets do exist. One—irradiation—has a 99.99% pathogen kill rate.

Of course, most of the general public has a fixed view of irradiation, with many believing they will glow after consuming irradiated products. Those who are informed know better. Estimates show that irradiating ground beef would add anywhere from 3 to 5 cents’ cost per pound, which seems like a small price to pay, considering these toxins’ ability to cause agonizing illness or death.

At the turn of the 20th century, the general public viewed pasteurization in the same way many perceive irradiation today. They didn’t understand its benefits. Over time, pasteurization was understood and standardized. Perhaps one day in the early 21st century the meat industry will be as lucky. Oh, and the second silver bullet? That would be to become a vegetarian or vegan. But make sure you wash and cook your veggies well before consuming them, because a cattle ranch may be upstream. Just ask Taco Bell.

Sayer is president of S&R Consulting, Alisa Viejo, Calif. Reach him at (909) 590-3340 or steve_sayer_westland@yahoo.com

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