FoodNet: Getting the Big Picture on Foodborne Disease

I work as an epidemiologist with CDC’s Foodborne Diseases Active Surveillance Network, otherwise known as FoodNet. My job is to study who gets sick and why and share this information with groups and persons whose goal is to reduce the amount of foodborne illness in the United States.

FoodNet is a collaborative project of the CDC, FDA, USDA, and 10 state health departments across the United States. These 10 areas cover 46 million people, or about 15 percent of the U.S. population. We collect information on seven bacteria that cause foodborne illness, such as Salmonella and E. coli O157 as well as two parasites, Cryptosporidium and Cyclospora.

Last week, we released a report on the data that we collected and analyzed for 2009. Here are two key findings from our report, along with tips on how you can reduce your risk of illness:

First, we observed recent successes in fighting E. coli O157:H7. The rate of infection with this dangerous kind of E. coli significantly decreased in 2009, reaching the lowest level since 2004. This type of E. coli is of particular concern because it can cause kidney failure. This infection is especially dangerous for children and the elderly. To help prevent infection with E. coli O157:H7, always cook ground beef and other meats to a safe temperature (use a meat thermometer to check) and avoid unpasteurized juices and milk.

Second, we also observed an increase in Vibrio infections. Vibrio is a type of bacteria that can cause disease in people who eat contaminated seafood, usually raw or undercooked oysters or other shellfish. We found that Vibrio infections increased by 85 percent over the past decade or so. While the overall number of these infections is a small percentage of all foodborne illnesses, the infection can cause severe illness or death, particularly in people with weakened immune systems. To prevent this type of infection, avoid eating raw or undercooked shellfish.

Also, I encourage you to always follow the four food safety steps:

• Clean: Wash hands, utensils, and cutting boards before and after contact with raw meat, poultry, seafood, and eggs to avoid spreading bacteria when preparing food.
• Separate: Use different cutting boards for meat, poultry, seafood, and vegetables and keep raw meat, poultry, seafood, and eggs apart from foods that won’t be cooked.
• Cook: Use a food thermometer. You can't tell if a food item is done by how it looks.
• Chill: Keep your refrigerator at 40 degrees or below to keep bacteria from growing, and chill leftovers and takeout foods within 2 hours.

For more information about FoodNet, visit the CDC FoodNet site.

Questions and Answers

Posted May 3, 2010

Q:  It seems to be more foodborne illnesses now than in the past. Is it?

A:  The CDC’s FoodNet MMWR report, which was released earlier this month, indicates that the rates of six different foodborne illnesses have declined when compared with 1996-1998. However, most have shown little change since 2004. The notable exceptions in the report are E. coli O157:H7 infections, which declined to their lowest point since 2004, and Vibrio infections, which increased by 85% when compared with 1996-1998. For more details, see Incidence of Foodborne Illness, 2009.

Q:  I wonder why we hear only from E coli O157:H7 and we do not hear from other pathogenic E coli strains.

A:  Currently, data are limited on non-O157 Shiga toxin-producing Escherichia coli (STEC). Many clinical laboratories do not test for non-O157 STEC infection because it is more difficult than identifying E. coli O157.

Q:  Can the decrease in E. coli O157:H7 be attributed to any practice or preventive control?

A:   The recent decrease in E. coli O157:H7 (STEC O157) infection might reflect, in part, control efforts in ground beef processing and produce growing practices. Consumers can reduce their risk of foodborne illness, such as E.coli O157:H7, by following safe food-handling and preparation recommendations, and by avoiding consumption of raw or undercooked foods of animal origin such as eggs, ground beef, and poultry; unpasteurized milk; and raw or undercooked oysters. Risk also can be decreased by choosing pasteurized milk and eggs, high pressure-treated oysters, and irradiated food products. Everyone should also wash hands after contact with animals and their environments.

Consumers should follow the easy lessons of "Clean, Separate, Cook, and Chill” as mentioned in this blog.