State Epidemiology, how can I help you? You had a party this weekend and 40 people who were at your party are now ill? While we have all seen the large food recalls of contaminated food or the latest outbreak of foodborne illness on the news, we usually don’t think getting sick can happen to us. However, roughly 48 million people in the United States come down with a foodborne illness each year. That’s roughly 16 percent of the entire United States getting sick each year because of something they ate. Foodborne illness is caused by consuming contaminated foods or beverages. Many different disease-causing microbes or pathogens can contaminate foods, so there are many different types of foodborne illnesses. Most foodborne diseases are infections caused by a variety of bacteria, viruses, and parasites. Other diseases are poisonings caused by harmful toxins or chemicals that have contaminated food. People have always gotten sick from food, but with our increased knowledge of pathogen transmission and our ability to determine the source of an illness, foodborne outbreaks are more readily recognized. Food can become contaminated in countless ways during its journey from farm to fork. However, most contamination falls into three areas during the journey from farm to fork – during growing or preharvest, production or post-harvest, or final processing and handling before food is eaten or sold. When food is being grown on a farm, it may be irrigated with water unknowingly contaminated with animal waste that ran into the lake that’s used for irrigation. This food is contaminated during the growing process. For foods of animal origin, contamination with disease-causing bacteria may occur at the time of slaughter or shortly thereafter. That’s when bacteria in the animal’s intestinal tract, such as Salmonella, can get on the surface of the product. Harmful bacteria such as Salmonella often colonize the intestinal tract of an animal, and in turn, get on the animal’s skin or feathers. When the animal is slaughtered, these bacteria can contaminate the surface of the raw meat or poultry. Foods such as deli meat and hot dogs can also be contaminated in factories by microorganisms such as Listeria, which can live in the factory environment. The third common cause of food contamination occurs as a result of how food is handled before being served or purchased. For example, the owner of a catering business takes thawed chicken out of the refrigerator to prepare it for cooking. She places it on the countertop to de-skin it prior to cooking. She gets busy and forgets to clean the countertop. After cooking the chicken, she places it back on the unwashed countertop to cool and cut up. She leaves it on the countertop for four hours before returning it to the refrigerator, allowing the foodborne bacteria to happily multiply. The next day, she serves the chicken in her famous cold chicken salad sandwich appetizers. Bon appetit! Foodborne illness is entirely preventable. During the past century in the United States, our public health predecessors and the food industry have successfully reduced or eliminated the burden of many foodborne pathogens, such as Typhoid fever. The burden of these foodborne diseases was reduced through the combined effort of better sanitation, public health surveillance and outbreak investigation, and food processing improvements such as pasteurization, refrigeration and freezing, commercial canning procedures, and the implementation of hazard analysis and critical control points (HACCP). In some instances, development of vaccines has played a role in reducing disease incidence. Even though we’ve had these advances, problems with foodborne illnesses still occur. We are continuing to identify differences in the pathogens causing illness and the people becoming ill. These differences reflect changes in the way our modern society produces and handles food, changes in dietary patterns, the international source for much of the food we eat, as well as changes in the susceptibility of portions of our population to illness. People who are more likely to become ill include young children and the elderly. Or those who have illnesses that reduce their resistance to an infection, such as HIV or cancer. The leading causes of foodborne illnesses in the United States today are norovirus, Salmonella, and Clostridium perfringens, with over 50% caused by norovirus alone. The highest cause of death from foodborne illness are Salmonella, Toxoplasma Gondii, and Listeria Monocytogenes. In recent years, trends in foodborne illness in the United States include increases in the incidence of Salmonella, Campylobacter, and Vibrio, and a decrease in incidence of Yersinia, Listeria, Shiga toxin-producing Escherichia coli O157, and Shigella. In addition to the health burden, the financial burden of the individual and industry can be heavily impacted as a result of foodborne illness or outbreak. Financial implications to an individual may include lost wages or job, medical care costs, and an ongoing physical disability. Foodborne outbreaks can have devastating financial impacts on the industry including cost to recall contaminated food, reduced consumer demand for the implicated product or brand, cost to implement food safety process improvements, potential lawsuits, imposed fines by government regulators, and marketing efforts to drive improvement of consumer product or brand perceptions after an outbreak. In the face of a potential foodborne outbreak, public health investigators hold a difficult position. When a foodborne outbreak is detected, the public must be rapidly informed to reduce potential morbidity and mortality. However, public health workers must realize that this critical objective is not without consequences and that accurate empirical evidence must be obtained and followed prior to any public announcement as some of your fellow citizens’ livelihoods will inevitably be negatively impacted. I still don’t fully understand how hundreds of people can become ill from a single food source. Has our food production system changed that much? Today our food production system is global in scale and vastly complex. But let’s go back in time to gain a better understanding of how the human food production system has evolved and how large multistate foodborne outbreaks can occur. The first evidence of human food production emerges during the Neolithic Era around 9500 B.C. Prior to then, humans are thought not to have used agriculture, but were hunter-gathers sharing limited amounts of food among small, geographically dispersed groups. With the advent of agriculture, food was available in sufficient quantities to sustain human settlements. However, as these settlements grew, so did the potential threat of disease transmission from interaction among humans, increases in human waste, and an ever-growing need for more livestock. Undoubtedly, many of these diseases were foodborne pathogens. During the following centuries, agriculture improvements allowed for an increase in the scale of the food system. And it was the industrial revolution that brought about a whole new food production paradigm. One of the key elements in this new model was transportation. Investments in railroads and canals made it faster and more efficient to move food from the field to a central processing facility. As a result, food grown out in the Great Plains of the United States could be shipped to Chicago or New York for processing and then out to the populous retail markets before spoilage. While the new food production model reduced financial costs for producers and consumers alike, it also increased the risk for foodborne illness. If food was contaminated in the central processing facility, for example through poor sanitation practices, that food was now reaching many more people. The mechanical, technological, and biological advances realized in the past 100 years have allowed a regional and then nation-wide food production system to rapidly expand into an intertwined global food market. Today, consumers experience in their local grocery store relatively cheap, fresh products from around the world to allow for year-round availability. In addition, grocery stores in the United States have undergone a transformation in the number of items they offer to consumers. In 1960, grocery stores sold on average 5,900 separate products. By 1979 that number increased to 7,800. These numbers are dwarfed by today’s standards where a grocery store sells on average 42,686 separate products. Even a small slip in food safety among the large number of different products sold today has significant potential to cause illness in many people. Through diligent public health work and regulation, safe food in the modern age has become widely available and is now expected by consumers. However, oversight on the global food production system to ensure all produced food is safe is not possible. Most food producers ensure their products meet the highest of standards. However, when food contamination events do occur, they are likely to have a regional, national, and potentially even a global effect because of our modern food production model. Therefore, a large number of people are potentially at risk of developing illness. While egregious food contamination is readily identified by public health surveillance systems, low-level food contamination is difficult to detect due to fewer people becoming ill across a wide food distribution area. To react to the changing food production system, public health surveillance systems are employing the use of new laboratory and technological techniques to allow public health investigators greater probability in detecting foodborne outbreaks that have cases spread across large geographical areas. As a result, local and state public health foodborne outbreak investigators may find themselves working with national partners at CDC and FDA to put the pieces together to solve a foodborne outbreak. In our next video, we’ll introduce you to the United States Federal agencies that regulate the food industry and investigate foodborne outbreaks, particularly looking at how they can assist state and local public health officials during foodborne outbreaks.