Top-10 food-pathogen combos for risk reduction efforts

If policy types are going to focus resources, it helps to know where to get the most bang for the regulatory dollar.

Researchers at the University of Florida Emerging Pathogens Institute have attempted to identify the Top 10 riskiest combinations of foods and disease-causing microorganisms.

The report, Ranking the Risks: The 10 Pathogen-Food Combinations with the Greatest Burden on Public Health, lists the number of illnesses, costs, and overall public health burden of specific microbes in particular types of food. The list includes:

Campylobacter in poultry — costs $1.3 billion a year
Toxoplasma in pork — costs $1.2 billion a year
Listeria in deli meats — costs $1.1 billion a year
Salmonella in poultry — costs $700 million a year
Listeria in dairy products — costs $700 million a year
Salmonella in complex foods — costs $600 million a year
Norovirus in complex foods — costs $900 million a year
Salmonella in produce — costs $500 million a year
Toxoplasma in beef — costs $700 million a year
Salmonella in eggs — costs $400 million a year

“The number of hazards and scale of the food system make for a critical challenge for consumers and government alike,” said Michael Batz, lead author of the report and head of Food Safety Programs at the Emerging Pathogens Institute. “Government agencies must work together to effectively target their efforts. If we don’t identify which pairs of foods and microbes present the greatest burden, we’ll waste time and resources and put even more people at risk.”

Of these, the new report concludes that five leading bugs—Campylobacter, Salmonella, Listeria monocytogenes, Toxoplasma gondii, and norovirus – result in $12.7 billion in annual economic loss – with the Top 10 pathogen-food combinations responsible for more than $8 billion. That burden includes the cost of medical care and lost productivity from employee sick days, as well as the expense of serious complications or chronic disabilities that result from the acute illness or sometimes strike after acute illness goes away.

Douglas Archer, associate dean for research at the UF Institute of Food and Agricultural Sciences who reviewed the report, told The Gainesville Sun, "You can’t inspect away foodborne illnesses.”

Of course, a farming rep told the Sun, food producers have to be diligent in ensuring food safety, but the public also has to play a role.

Frankie Hall, director of agricultural policy for the Florida Farm Bureau said, producers can do a good job only to have the person who takes the food home handle it improperly, adding, "There is responsibility for food safety when you get it back to the home.”

J. Glenn Morris, the director of the Emerging Pathogens Institute at the University of Florida and one of the authors of the study told the Washington Post that policymakers at the USDA, which regulates meat, poultry and some egg products, and the FDA, which oversees the rest of the food supply, should consider the economic burden on society when deciding how to direct food safety resources, adding, “You can begin to use these more sophisticated analytic tools, which can serve as the basis of spending public dollars in terms of food safety.”

The report, which was supported by a grant from the Robert Wood Johnson Foundation, includes the following key findings and recommendations for food safety officials:

• Poultry contaminated with Camplylobacter bacteria topped the list, sickening more than 600,000 Americans at a cost of $1.3 billion per year. Salmonella in poultry also ranks in the Top 10, with $700 million due to costs of illness. Infections with these microorganisms can cause acute illness such as vomiting but also can lead to hospitalization or death. Campylobacter infection can also cause paralysis and other neuromuscular problems. The report questions whether new safety standards announced by the USDA for young chickens and turkeys are sufficient, and recommends evaluating and tightening these standards over time.

• Salmonella is the leading disease-causing bug overall, causing more than $3 billion in disease burden annually. In addition to poultry, Salmonella-contaminated produce, eggs and multi-ingredient foods all rank in the Top 10. The report recommends that the FDA and USDA develop a joint Salmonella initiative that coordinates efforts in a number of foods.

• Four combinations in the Top 10 – Listeria in deli meats and soft cheeses, and Toxoplasma in pork and beef – pose serious risks to pregnant women and developing fetuses, causing stillbirth or infants born with irreversible mental and physical disabilities. The report recommends that agencies strengthen prevention programs for these pathogens and improve education efforts aimed at pregnant women.

• Norovirus is the most common foodborne pathogen and is largely associated with multi-ingredient items that can become contaminated, often by service-industry workers who handle food. The researchers recommend strengthening state and local food safety programs through increased funding, training and adoption by states of the most recent FDA Food Code.

• The report lists E. coli O157:H7 as the sixth pathogen in overall burden, with the majority due to contaminated beef and produce. The report recommends federal agencies continue to target E. coli O157:H7, due to the particularly devastating injuries it causes in small children, including kidney failure, lifetime health complications, and death.

The report is available at:

Acuff speaks, over and over and over (because it’s on video at***

Dr. Gary Acuff game a seminar at Kansas State University on Nov. 9, 2010, entitled, The End Game: What is Really Achievable in Pathogen Reduction.

The slides for Acuff’s talk are available at:

The video is available at:

Or under the video section on the front page of

Texas A&M University announced last month that Acuff was going to become director for the Center for Food Safety, and will lead expanded food safety efforts.

Prior to his appointment as Director of the Center for Food Safety, Acuff served as interim head and then head of the department of animal science from 2004 to 2010. And before that he taught undergraduate and graduate level courses and laboratories in food microbiology for 20 years and conducted research on the microbiological quality and safety of foods through his appointment with Texas AgriLife Research.

A past-president of the International Association of Food Protection, Acuff currently is chairman of a 10-member committee for the National Research Council, which evaluates food safety requirements for the Federal Purchase Ground Beef Program.

Lowering loads: food safety starts on the farm

Every time some government type says there are more cases of E. coli O157:H7 and other dangerous bacteria in the summertime because people barbeque more, I cringe. It’s one of those blame-the-consumer comments when the reality is more complicated. 

Most food safety interventions are designed to reduce or eliminate pathogen loads – to lower the number of harmful bugs from farm-to-fork. A piece of highly-contaminated meat can wreck cross-contamination havoc in a food service or home kitchen.

Elizabeth Weise writes in USA Today today that animals carry higher levels of E. coli O157:H7 and friends during the summer months, and summarizes efforts to lower bacterial loads on animals entering slaughter plants.

Jerold Mande, USDA deputy undersecretary for food safety, said last month,

"To take the next big step forward on food safety, we need to do more to have fewer pathogens on food animals when they arrive at the slaughterhouse gate.”

Jim Marsden of Kansas State University said that microbiologically, the biggest "bang for the buck" is cleaning the bacteria off the hide or the carcass to keep it from coming into contact with the meat.

Weise writes that a number of possible interventions are in the works. Each, it is hoped, might take down the incidence of E. coli O157:H7 by a factor of 100. Below is the edited list.

Vaccines: Gut warfare

Probably the most hopeful are vaccines that lower the amount of O157:H7 in cattle’s guts. Two are furthest along, one from a Minnesota company called Epitopix and one by a Canadian company called Bioniche Life Sciences. Epitopix’s vaccine has received preliminary approval from the USDA and is being tested in the USA. Bioniche’s vaccine was approved in Canada last year and is in the approval process in the USA. In addition, scientists at the USDA’s National Animal Disease Center in Ames, Iowa, have developed two more vaccines.

Field trials of the Epitopix vaccine showed that 86% of vaccinated cattle stopped shedding O157:H7 bacteria in their feces. Of those that still were shedding bacteria, there was a 98% reduction in the amount, says Daniel Thomson (left, photo from USA Today), a veterinarian and professor of Production Medicine at Kansas State University in Manhattan, Kan., who has studied the effectiveness of vaccine for the company.

The issue for cattlemen will be the costs of the two or three shots necessary to create immunity and the wear and tear on the cattle caused by bringing them in to be vaccinated. Going through the chute that holds them still while they’re given the shot, necessary to safeguard workers, can cause some cattle to become agitated.

Phages: A spray of bacteria fighters

Cattle walking through a car-wash-like spray of bacteria-eating viruses called phages sounds more science fiction than feedlot, but it’s actually in use across the USA. In cattle, a phage that is specific to E. coli O157:H7 is sprayed on the animals one to four hours before they’re slaughtered. "They like to have them soak," says Dan Schaefer, director of beef research and development at in Wichita. Cargill is testing the spray at one of its plants.

Probiotics: ‘Exclusion’ cultures

Basically these are bacterial cultures much like those in yogurt, given to cattle in their feed. They’re called "competitive exclusion" cultures because they out-compete the bad bacteria and exclude them in the animals’ guts. Michael Doyle, director of the Center for Food Safety at the University of Georgia in Griffin, spent years investigating them.

One for E. coli O157:H7 "worked really well for a while and then it stopped working for a while," he says. Doses required are often higher than those claimed by the companies that sell them, he says. Currently these aren’t approved by USDA or FDA as E. coli reduction methods, so the companies that market them can’t make any specific claims for them.

Sodium chlorate: A ‘suicide pill’

This chemical is used in part to do environmentally safe paper bleaching. But administered in extremely small amounts, it also plays a deadly trick on E. coli O157:H7 and salmonella.

In the oxygen-free environment of a cow’s gut, these bacteria are able to obtain energy from nitrogen. But they can’t tell the difference between nitrogen and chlorate, so if there’s chlorate present, they try to use that. This turns the chlorate into bleach, killing the bacteria from the inside without harming the animal.

Grain vs. high-quality hay

Research in Texas, Kansas and Idaho has shown that switching cattle from grain to a more expensive diet of high quality hay before slaughter may lower E. coli O157:H7 rates, though the findings have not always been consistent.

From an epidemiologic standpoint, it’s clear that these pre-slaughter interventions lower the E. coli O157:H7 burden in the cattle, says Guy Loneragan, a professor of animal science and expert in O157:H7 in cattle at West Texas A&M University in Canyon, Texas.

The question is whether investing money on the ranch and feedlot will save money at the packing plant.