Introduction to Emerging Microbiological Food Safety Issues

The continued occurrence of foodborne illness is not evidence of the failure of our food safety system. In fact, many of our prevention and control efforts have been—and continue to be—highly effective. Despite great strides in the area of microbiological food safety, much remains to be done. Foodborne illness is not a simple problem in need of a solution; it is a complex combination of factors that must be managed on a continual basis. Changing life-styles and population demographics, global food trade to provide a year-round supply of fruits and vegetables, and novel foods are a few examples of potential food safety issues. No matter how sophisticated and complex a system is developed, food safety management is never finished or complete, because change is constant.

Trinity of Factors

At the simplest level, foodborne illness can be reduced to three factors: the pathogen, the host, and the environment in which they exist and interact. When one or more of the three factors changes, new foodborne pathogens “emerge.” These three factors are also the key to reducing foodborne illness. Prevention and control efforts often focus on the contribution of one of these factors; however, in many cases, the most effective approach addresses more than one factor. Current technologies and production methods cannot provide a food supply that is completely free of all pathogenic microorganisms. Fortunately, even small reductions in several factors can have a substantial combined effect.

Evolution of Controls and Policies

New technologies, production practices and food manufacturing processes are developed to meet the needs of a changing society. New technologies with increasing sophistication have yielded continued improvements in microbiological food safety while delivering better quality foods with greater nutritional value and superior sensory characteristics. However, our growing knowledge base continues to expose the role of various foods and technological innovations in foodborne hazards. Furthermore, changes in the food, the consuming public, and the pathogens themselves continue to make foodborne disease an important and ever-changing challenge both for the industrialized and the developing world.

Current U.S. food safety policies are the accretions of decades of relatively independent efforts to address specific problems. Most are rooted in the sanitary revolution that occurred at the beginning of the 20th century, and they have characteristics that have served us well during the transition from an agrarian to an industrialized society. However, estimates of the incidence of foodborne illness clearly show that, in some cases, the existing approaches to control is inadequate.

Foodborne Illness

In the United States, the Centers for Disease Control and Prevention have estimated that foodborne pathogens cause approximately 76 million illnesses, 325,000 hospitalizations, and 5,000 deaths each year. More than 200 known diseases are transmitted through food, and more than half of all recognized foodborne disease outbreaks have unknown causes, indicating the real number of disease-causing agents is likely much larger than 200. The symptoms of foodborne illnesses range from mild gastroenteritis to life-threatening neurologic, hepatic, and renal syndromes.

A pathogen’s ability to cause illness can be very different from the severity of the illness it causes. Some pathogens cause a great number of illnesses but the fatality rate is very small. Others cause few illnesses, but many of those illnesses are fatal. Prioritizing our food safety management efforts will be difficult, but doing so is essential to maximize the public health benefit of these efforts.

Food Safety Management

Just as food safety issues change over time, so too must our management strategies and our regulatory framework. Continued research will improve our understanding of the complex factors that cause foodborne illness, and surveillance programs will gather data to document the effectiveness of our controls and identify new problems as they emerge. A science-based food safety management framework should use Food Safety Objectives to translate data about risk into achievable public health goals.

Managing microbiological food safety is a complex task that requires the involvement of all facets of the food industry, regulatory and allied professionals, and consumers. It is critically important that regulatory policies and food safety management efforts be based on the best science currently available. For this reason, food safety policies must be flexible to incorporate scientific knowledge in a product- and process-specific manner.


Recognizing that food safety is a fundamental and continuing issue, the Institute of Food Technologists commissioned an expert panel to review the available scientific literature related to emerging microbiological food safety issues. The panel’s report is divided into seven sections: Introduction, Pathogenicity, Human Hosts, Microbial Ecology, Application of Science to Food Safety Management, Next Steps, and Conclusions. Copies of the report are available at www.ift.org.