CDC Report Shows Success in Fighting E. coli O157:H7

The rate of a severe form of Escherichia coli diarrhea significantly decreased in 2009, reaching the lowest level since 2004, according to a report released by the Centers for Disease Control and Prevention (CDC).

 The incidence of the disease, called Shiga toxin-producing E. coli (STEC) O157 infection, also met the national 2010 Healthy People target in 2009.  Infection with E. coli O157 is of particular concern because in 5 percent to 10 percent of cases the infection causes kidney failure and it can be especially dangerous for children and the elderly.

The data were collected through CDC’s Foodborne Diseases Active Surveillance Network, known as FoodNet, the most complete and up-to-date source of information about trends in foodborne illnesses in the United States. FoodNet conducts active surveillance for nine pathogens commonly transmitted through food, and leads studies designed to help health officials better understand how foodborne diseases are impacting Americans. Annual data are compared with data from the previous three years and with data from the first years of surveillance (1996-1998) to analyze trends and measure progress.

While the 2009 rates of most of the nine illnesses that are tracked through FoodNet sustained the declines seen since FoodNet began in 1996, most have shown little change since 2004.

"The interventions begun in the late 1990s were successful in decreasing some of these foodborne diseases, but we haven’t seen much recent progress,” said Chris Braden, MD, acting director of CDC’s Division of Foodborne, Waterborne, and Environmental Diseases. “To make additional strides against these diseases and ultimately better protect the American people from foodborne illness, CDC, our federal and state partners, and the food industry will need to try new strategies."

"Today’s report confirms our past success combating foodborne illness by setting an aggressive goal, designing an effective system to meet that goal, and relentlessly implementing it; it’s time to do it again," said David Goldman, MD, MPH, assistant administrator in the Office of Public Health Science of the U.S. Agriculture Department’s Food Safety and Inspection Service. 

Following the 1993 outbreak of E. coli O157:H7, the government declared O157 an adulterant, implemented Hazard Analysis and Critical Control Point (HACCP) production systems to prevent food contamination, established FoodNet and PulseNet, and set a goal of cutting O157 illnesses in half by 2010. 

"There is more work to do," Goldman said. "Under the President’s Food Safety Working Group we are setting new goals and modernizing the system to meet those goals so that we can see renewed progress in cutting foodborne illnesses."

“FoodNet data are important in helping FDA to design food safety policies and programs to reduce foodborne illness," according to Jeff Farrar, DVM, MPH, PhD, associate commissioner for food protection in the Food and Drug Administration. “FDA is pursuing a number of initiatives to strengthen the foods program, such as new preventive measure requirements during the production of shell eggs to address Salmonella Enteritidis. This measure will become effective this summer. FDA also is developing a proposed rule that includes risk-based safety standards for preventing illness from produce, and it is expected to be published within a year.”

The only significant decline in incidence in recent years other than for E. coliO157 was for Shigella infections. Although some Shigella infections are transmitted by food, most are probably transmitted directly from one person to another, often among children in child care settings, rather than through food.

Vibrio infections increased by 85 percent compared with the first three years of surveillance. While the overall number of Vibrio infections is a small percentage of all foodborne illnesses, the infection may cause severe illness or death, particularly in people with weakened immune systems. Most Vibrio infections are the result of eating raw or undercooked shellfish, especially oysters.

Among the four pathogens tracked in FoodNet that have national incidence goals, Salmonella is furthest from meeting the goal. One possible reason for the slow progress in fighting Salmonella is that it is spread through a wide variety of foods, and also through non foodborne routes. Salmonella can be spread by poultry, meat, eggs, produce and processed foods, as well as by contact with animals like baby chicks, small turtles, reptiles and frogs.

For most of the infections, the rate was highest in children under the age of 4 years. People over 50 years old had the highest rates of hospitalizations and deaths from most foodborne illnesses, emphasizing the need for those over 50 to get diagnosed and get treatment quickly after becoming ill.

To reduce their risk of foodborne illness, consumers should assume raw chicken, meat and eggs carry bacteria that can cause illness and should not allow them to cross-contaminate surfaces and other foods. They should also cook chicken and meat to a safe temperature as measured by a food thermometer, avoid unpasteurized milk and unpasteurized soft cheese and make sure shellfish are cooked or pressure treated before eating.