Published on 01/29/04

Scientists propose new approach to food safety

By Cat Holmes
University of Georgia

Mad cow disease has grabbed more headlines lately, but the germs that cause foodborne illnesses have a much greater impact on public health. Now a task force of U.S. scientists is proposing new ways to tackle food safety.

The Centers for Disease Control and Prevention estimate that each year foodborne illnesses make 76 million Americans sick, put more than 300,000 in hospitals and kill 5,000 people.

An issue paper released by the Council for Agricultural Science and Technology recommends new strategies to enhance food safety, specifically food derived from animals.

“The bottom line is to come up with a strategic approach to reduce the incidence of foodborne illness,” said Michael Doyle, director of the University of Georgia Center for Food Safety and chair of the CAST task force.

The task force is made up of scientists from around the United States. They found that the best approach to the problem was quantitative microbial risk assessment. Translation: a systems approach in which each food source is examined from the farm to your plate.

“The idea is to determine where in the system we would have the greatest impact,” said Doyle, an international authority on foodborne bacterial pathogens. “From a public health and regulatory standpoint, we have limited resources, so the idea is to find the points where we can intervene and most greatly reduce the risk of human illness.”

For example, take the case of listeriosis, a serious infection that mainly affects pregnant women, newborns and adults with weakened immune systems. According to the CDC, 2,500 Americans become seriously ill with listeriosis each year and 500 die.

Listeria is killed by pasteurization and cooking, but certain ready-to-eat foods like hot dogs and deli meats can be contaminated after cooking and before packaging.

“In this case, the greatest impact for reducing listeriosis would be interventions in the meat processing plants,” Doyle said.

However, in the case of Escherichia coli O157:H7, another foodborne illness that infects 73,000 people and kills 61 each year in the U.S., the place of greatest impact is most likely the farm.

“Reducing E. coli O157:H7 carriage in cattle is likely to have a greater impact on reducing human illness than relying on cooking ground beef thoroughly,” Doyle said.

That’s because E. coli is transmitted not only through eating undercooked, contaminated ground beef but also through cattle manure on the farm and in water that may be used for drinking, swimming or irrigation.

Keeping the pathogen out of the cattle will not only protect the beef supply but also water, farms and produce.

The CAST paper addresses not only the safety of foods during production but also food safety initiatives for consumers and retailers.

The full text of the paper, "Intervention Strategies for the Microbial Safety of Foods of Animal Origin," (Issue paper No. 25) is on the CAST Web site (

CAST is an international group of 38 scientific and professional societies. It gathers, interprets and communicates science-based information about food, fiber and natural resources.

(Cat Holmes is a news editor for the University of Georgia College of Agricultural and Environmental Sciences.)

Cat Holmes was a science writer with the University of Georgia College of Agricultural and Environmental Sciences.