The U.S. food supply is among the safest in the world. However, public health officials estimate tens of millions of Americans are made ill by food-associated pathogens annually. Considering the hundreds of billions of food servings consumed in the U.S. each year, that's a relatively small percentage of illnesses per serving. Still, more can be done to further reduce foodborne disease, especially illnesses resulting in kidney failure or meningitis.

During the past decade, illnesses caused by foodborne pathogens were reduced by 30-50 percent. Also, occurrences of many types of foodborne pathogens in foods such as meat and poultry were reduced. So, yes, the U.S. food supply is safer today. However, major food-associated outbreaks continue to occur, indicating more needs to be done to provide greater public health protection.

There's considerable variation in the sanitary conditions under which food is produced in different countries. It's not possible to generalize regarding the safety of imported foods. However, food from countries with inadequate sanitary practices, such as improper use of manure for growing food crops and failure to use good hygienic practices by food handlers in harvesting and preparing foods, is more likely to be contaminated with harmful microorganisms than foods produced under sanitary conditions.

Fresh produce is one of the leading vehicles of cases of foodborne disease associated with outbreaks and will likely continue to be a public health concern as the percentage of produce imported into the U.S. continues to increase. More than 25 percent of fresh produce consumed in the U.S. is imported, and much comes from countries with inadequate sanitary practices. However, U.S.- grown produce has also been a common vehicle of foodborne outbreaks.

Our faculty largely focuses on developing better detection, control and elimination methods of foodborne pathogens throughout the food chain. An important part of this is elucidating the ecology of foodborne pathogens by defining how they colonize animals and plants. An example is determining how campylobacters and salmonellae colonize the intestinal tract of poultry and developing methods, such as competitive exclusion bacteria and bacteriocins, to reduce pathogen carriage.

Studies also have been done to determine locations on fruits and vegetables, including apples and lettuce, of E. coli 0157:H7 attachment and internalization and developing novel interventions, such as hydrogen peroxide with mild heat, to treat produce such as cut lettuce and still yield a product that consumers accept and has a reasonable shelf life. Recent trace-back results from FDA and State of California investigators of an E. coli 0157:H7 outbreak associated with bagged spinach identified the importance of cattle manure as the source of the pathogen. CFS faculty members are determining the best practical conditions for preparing dairy manure-based compost to kill E. coli 0157 as well as Salmonella and Listeria before application to soil. Studies are also being done to develop methods for detecting and inactivating parasites and viruses in foods.

Following an outbreak of E. coli 0157:H7 infection in which more than 700 people were made ill from undercooked hamburgers, the USDA mandated development and implementation of Hazard Analysis Critical Control Point systems by the meat and poultry industry. This, in large part, involved developing practical treatments to kill and control harmful microorganisms and applying them in slaughter and processing operations. This was a highly successful approach, leading to major reductions in the prevalence of pathogens like E. coli 0157:H7, Salmonella, Campylobacter and Listeria monocytogenes in fresh meat and poultry and to subsequent reductions in the incidence of foodborne disease caused by these pathogens. Other segments of the food industry, including the produce industry, need to adopt effective HACCP systems and apply them throughout the food chain, from production through consumption.