Food Protection Connection: Tracking Foodborne Illness

(reprinted from Dietary Manager, May 2010)

Over recent years, how has our rate of foodborne illness changed? Which pathogens are on the rise? Or the decline? Which emerging strains of pathogens are posing new threats? Are our food protection efforts working?

These are crucial questions for everyone concerned with food protection efforts. Fortunately, we have powerful information systems in place to provide exactly this kind of information. For example, we know that foodborne illness from Vibrio, Cryptosporidium, and Salmonella increased from 1998 to 2008. This is thanks to the active surveillance of a national program called FoodNet.

FoodNet combines the resources of the Centers for Disease Control (CDC), USDA, FDA, and state health departments to track foodborne illness, test and verify cases of foodborne illness outbreaks, and amass data for comprehensive statistical analysis. Its goals are to:

• Determine the burden of foodborne illness in the US
• Monitor trends over time
• Attribute the burden of foodborne illness to specific foods and/or settings
• Develop targeted interventions to prevent foodborne illness

Essentially, FoodNet operates on the concept that knowledge is power. The more we know, the more we can do to ensure public health. FoodNet collects information through active surveillance systems.

Active Surveillance
What does active surveillance really mean? It’s the opposite of passive surveillance, in which health departments rely on the public to report illness, and the CDC relies on health departments to do likewise. We know this leads to under-reporting and major gaps in information. According to the CDC, “A complex chain of events must occur before such a case is reported, and a break at any link along the chain will result in a case not being reported.”

In contrast, active surveillance has health officials routinely contacting laboratories to solicit information. Officials focus on lab tests associated with diarrheal illnesses, since these can reflect foodborne illness. The FoodNet program addresses bacteria such as Campylobacter, Escherichia coli O157, Listeria monocytogenes, Salmonella, Shigella, Vibrio, and Yersinia enterocolitica, and parasites such as Cryptosporidium and Cyclospora. It does not monitor viruses, such as Norwalk or Hepatitis.

The Illness Pyramid
With an estimated 76 million cases of foodborne illness in the US annually, health officials describe the situation as a “foodborne illness pyramid.” The reality is that few cases make it to the tip of the pyramid. This is because so many steps are involved in foodborne illness reporting, according to the CDC:

• People are exposed to pathogens
• People become ill
• People seek care
• A specimen is obtained
• Laboratory testing takes place
• The lab confirms a case
• The case is reported to the CDC

Essentially, the FoodNet program works to keep the above steps connected. It tracks the tip of the pyramid to shed light on the entire profile. FoodNet surveillance covers more than 650 clinical laboratories and represents about 15 percent of the US population.

Trend Reporting
FoodNet reports establish trends and priorities that every dietary manager can put to use. For example, the most recent report (published in April 2009) defines the trends and risks for older Americans. It shows that hospitalization for foodborne illness is most likely for individuals over 50 years of age when any of the following pathogens are involved: Listeria (86.2%), E. coli O157 (53.3%), Vibrio (45.6%), Salmonella (40.0%), Yersinia (37.5%), Shigella (27.9%), Cryptosporidium (24.5%), and Campylobacter (20.5%). It also shows mortality rates, indicating that nearly one in five cases of Listeria illness among individuals over 50 results in death.

From this information alone, it makes sense to target Listeria control as mission-critical to food protection efforts in long-term care. How can you apply this information to staff training? Let’s put it into plain English: If we fail to monitor refrigeration temperatures for deli meats, or skip rotating stock as first-in first-out, or bypass taking endpoint cooking temperatures on hot dogs… in each case, we put clients at risk for Listeria-related illness. Four out of five clients may have to be hospitalized; one may lose a life. Real numbers can make the threat more real, and provide employees with a sense of purpose in food safety practices.

Reviewing Actual Outbreaks
Another service from the CDC allows Web visitors to research outbreak details through an interactive tool. OutbreakNet lets you retrieve actual outbreak information by year, by state, by location or foodservice type (e.g., home meal preparation, nursing home, hospital), and/or by pathogen or agent. For example, the system shows 101 confirmed cases of Norovirus outbreak in nursing homes in Wisconsin for January 2007.

Unlike FoodNet, Outbreak Net includes viruses, as well as chemical agents, such as histamine poisoning or monosodium glutamate (MSG). OutbreakNet also shows number of hospitalizations and deaths, as well as the associated food for each outbreak. Here is another example: It shows 40 confirmed cases of Salmonellosis from hollandaise sauce in California in August 2007. Two people were hospitalized; everyone survived.

Unlike some news headlines, OutbreakNet provides the final data on outbreaks, and lists only confirmed cases. It provides foodservice management professionals a way to explore common pathogens by foodservice segment and by geographic location.

Answers we often miss in headlines are evident: What really caused the outbreak? For example, the Salmonella Enteritidis trend for 2007 links to hollandaise sauce, scrambled eggs, banana pudding, bleu cheese dressing, homemade ice cream, and lasagna.

A review of confirmed Norovirus outbreaks in hospitals shows the virus transmitting through salads and sandwiches. Here is hard evidence that handwashing (or lack thereof) has an impact on the health of foodservice customers. What more could you need to create food safety controls appropriate to each item on your menu… and describe the food safety imperative to your team?

The CDC’s far-reaching data collection and analysis systems, as comprised by FoodNet and OutbreakNet, deliver a wealth of information not only to policy-makers, but to dietary managers, for meaningful trend details. Knowing the facts can help us change them for safer food service operations.

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More Info

FoodNet: www.cdc.gov/foodnet

OutbreakNet: www.cdc.gov/foodborneoutbreaks

by Sue Grossbauer, RD
Sue Grossbauer, RD, is president of The Grossbauer Group and the author of many ANFP publications and online courses. She supports foodservice organizations in areas relating to marketing, education, food safety, and technology.