1) According to 2006 data, are we on track to reach the national health objectives, as specified in Healthy People 2010, for reducing foodborne illness by 2010?
There are national health objectives for four types of foodborne infection, caused by Camplyobacter, Listeria, Salmonella and E. coli O157. According to 2006 data, we are on track to reach the Healthy People 2010 objective for Campylobacter. We did not reach the 2005 national health objective for Listeria, but we are approaching it. We are not on track to reach the 2010 national health objectives for E. coli O157 and Salmonella.
2) Why has the incidence of infections caused by E. coli O157 and Salmonella not declined since the 1996-1998 baseline?
Reasons for the lack of decrease in the incidence of infections caused by E. coli O157 and Salmonella are not fully understood. A marked decrease in E. coli O157 infections occurred in 2003 and 2004, but was followed by increases in 2005 and 2006. One possible explanation for this reversal is a shift in food vehicles. E. coli O157 lives in the intestines of healthy cattle, and not (to any great extent) in other food animals. However, ground beef is much safer now than it was five years ago, so it seems unlikely that the recent increase in infections would be due to ground beef. E. coli O157 from cattle ranches can get into the environment. Salmonella is carried in the intestinal tracts of most food animals (including cattle and poultry) and can also contaminate produce, so efforts are needed to more effectively prevent contamination of a variety of foods from farm to table. Several large, multi-state outbreaks of illness associated with the consumption of fresh produce in 2006 highlight the need to prevent contamination of produce that will be consumed raw. Regulatory agencies have introduced initiatives to respond to these trends.
3) How is the incidence of infections described by FoodNet influenced by outbreaks of foodborne diseases?
Outbreaks of foodborne diseases can cause the incidence of infections to increase. In 2004, FoodNet began collecting data on which laboratory-confirmed infections were associated with outbreaks. From 2004-2006, between 9% and 23% of E. coli O157 cases each year were associated with outbreaks, and 5-6% of Salmonella cases were associated with outbreaks. FoodNet will continue to collect data on which infections were outbreak-associated. In future years, this will allow FoodNet to comment on how outbreaks have affected the overall incidence of foodborne disease.
4) What do the 2006 FoodNet data tell us about the human health burden of foodborne diseases?
The 2006 FoodNet data tell us that incidence of infections caused by E. coli O157 and Salmonella is similar to that during the 1996-1998 baseline years, and Vibrio infections have increased. This indicates that further measures are needed to reduce the human health burden of certain foodborne pathogens.
5) How many cases of foodborne disease are there in the United States?
While it is difficult to precisely estimate the incidence of foodborne disease, in 1999 CDC estimated that 76 million cases of foodborne disease occur each year in the United States. Although many of these cases are mild and cause symptoms for only a day or two and most people do not seek medical help, some infections result in serious illnesses. Each year, foodborne diseases result in 325,000 hospitalizations and 5,000 deaths. The most severe cases tend to occur in the elderly, the very young, those who already have an illness that reduces their immune system function, and in healthy people exposed to a very high dose of an organism.
6) What are the limitations of the FoodNet data?
1. FoodNet relies on laboratory diagnoses, but only a fraction of all foodborne illnesses are
diagnosed by clinical laboratories.
2. Protocols for isolation of enteric pathogens in clinical laboratories are not uniform within and among FoodNet sites.
3. Reported illnesses might have been acquired through non-food sources, so incidence rates do not reflect foodborne transmission exclusively.
7) Are the data from FoodNet representative of the entire United States?
FoodNet is a useful gauge that provides valid and reliable information about incidence and trends of foodborne illness in the United States. FoodNet has increased from five sites since its launch in 1996 to the current ten sites, which has improved representativeness. A comparison of 2005 FoodNet and national census data suggested that differences in characteristics between persons who live within the FoodNet surveillance area and persons who live in the United States overall were limited. The only notable difference was the under-representation of the Hispanic population at FoodNet sites. Otherwise, data from FoodNet are generally representative of the entire United States.
8) What is CDC doing to control and prevent foodborne disease?
CDC performs surveillance, investigates outbreaks, conducts research, identifies prevention measures, and provides consumer education on foodborne illnesses. CDC researchers develop new methods for identifying, characterizing and fingerprinting the microbes that cause disease. CDC provides expert epidemiologic and microbiologic consultation to health departments and other federal agencies. CDC assesses the effectiveness of prevention efforts.
9) What can consumers do to reduce the risk for foodborne illness?
Consumers can reduce their risk for foodborne illness by following safe food-handling recommendations and by avoiding consumption of unpasteurized milk, raw or undercooked oysters, raw or undercooked eggs, raw or undercooked ground beef, and undercooked poultry. The risk for foodborne illness can also be decreased by choosing in-shell pasteurized eggs, irradiated ground meat, and high pressure-treated oysters. Additional information on food safety for consumers is available at http://www.foodsafety.gov/.
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